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^Photo-Eng 

HANDfKDK 

-ON- 


Etching 3 - 

—Finishing 



SECOND EDITION 



A condensed treatise on 
the Etching and Finish¬ 
ing branches of Photo- 
Engraving; with Miscel¬ 
laneous Chapters and an 
Appendix of practical 
examples, etc. 

(Illustrated.) 


BY 

J 


Copyright 1921 

(First Edition Copyright 1920.) 


: ;' 
















PREFACE. 



cA 


The Photo-Engraving Process can hardly 
he called altogether old, nor yet entirely new, 
but the rapid advancement in improved meth- 
dos, widely extended uses, and varied resultant 
achievements surely entitles it to a place in 
the front rank of pictorial reproduction and 
educational progress. It is a work little un¬ 
derstood by the average layman, and there is 
no vocation, perhaps, that requires a more 
inseparable combination of chemistry, art, and 
scientific skill. 

While there are numerous books on photo¬ 
engraving obtainable, there is very little de¬ 
tail published in regard to the Etching and 
Finishing branches of the art, practically all 
dealing principally with the subject of “oper¬ 
ating" or negative-making. That alone 
seems to be sufficient reason to justify the 
publication of this little hand-book. It is not 
intended as a complete encyclopedia of the 
processes, but rather as a guide and brief 
treatise in simple terms for the engraving 
student and apprentice in conjunction with 
their daily practical work. As such, it is 
hoped that it may be found valuable and use¬ 
ful. However, merely studying a book, or 
any number of books, without practical ap¬ 
plication, will not enable anyone to become a 
good photo-engraver. This accomplishment 
can be acquired only by patient practice and 
applied skill along with study and a keen in¬ 
terest in the work. 

At the back of the book will be found an 
Appendix, showing a few simple examples of 
varied methods in commercial use, not for the 
purpose of depicting any extraordinary sub¬ 
jects, but merely that the reader may have a 
clearer conception of the matter described in 
the treatise. All plates were made precisely 
in accordance with the instructions given. 




INTRODUCTION. 


Before proceeding further, it might be 
well to describe briefly the negative and the 
nature , of its requirements for our purpose. 

Practically any sort of subject (termed 
“copy”), whether a line drawing (pen and 
ink), photograph, wash drawing, water color, 
oil painting, or even the actual object itself, 
can be quite faithfully reproduced by photo¬ 
engraving. The first requirement now to be¬ 
gin our work is that a suitable photographic 
negative be made from the copy. The nega¬ 
tive is a photographic reproduction of the 
copy produced by the action of light reflected 
from the copy, through a photographic lens 
onto a silver-sensitized glass plate, the image 
on development being reversed as to light and 
shade, the whites on the copy being repre¬ 
sented by corresponding portions of balck 
denosits and the blacks by transparencies. It 
is most commonly (practically always except 
for color process work) made by the “wet-col¬ 
lodion” method, which gives extreme contrast, 
perfect density in the opaque parts and at the 
same time perfectly clear glass in the unex¬ 
posed portions when properly manipulated for 
our purpose. This negative is used for 
printing by the action of light onto sensitized 
metal for etching. 

The “Line Negative” then (usually from 
a pen drawing in black ink on white paper) 
is very simple, about the only requirement 
being that the white paper be represented by 
perfect opacity and the black lines by perfect 
transparency, the lines also corresponding in 
breadth proportionate to those on the copy. 

In reproducing the other subjects, how¬ 
ever, where different degrees of light and 
shade are required, a negative of different 
character is necessary. This is called a 
df “Half-tone Negative”, and is produced by 
^photographing the copy through a “half-tone 
.h screen”, thus breaking up the variations of 



light and shade into alternate solid and trans¬ 
parent dots of different shapes and sizes. The 
resulting half-tone negative depends on many 
different functions and scientific principles, 
especially those, relating to “screen separa¬ 
tion”, “stops”, and “exposure”. Such details 
must necessarily be omitted here. A properly 
made negative, however, is essential for the 
best work, and it will be sufficient to describe 
briefly the main points of a properly made 
half-tone negative. One accustomed to the 
work will then quite readily understand what 
is required. First, the “shadow dots” (black 
dots of silver sulphide deposit in the negative* 
shadows) must be quite small and very solid 
so as to not “print through” when subse¬ 
quently printing by arc light. Second, in the 
“middle-tones” the dots must close together 
and join in suitable proportion and shape, a 
true middle-tone being of a chess-board pat¬ 
tern, but in all cases quite solid and opaque. 
Third, in the “high-lights” (transparent holes 
in solid silver deposit as usually found in sky 
portions, etc.), the dots must join strongly 
and overlap, giving strong opaque connec¬ 
tions, leaving the transparent spots fairly 
small and just well rounded from the more 
nearly square in the next darker tones. That 
is, while at first glance one would expect to 
find them very small points of transparency 
corresponding in size to the shadow dots (as 
ds required for “offset process”), the trans¬ 
parent spots must be slightly larger than that 
at least, for reasons which' will be given un¬ 
der “Copper Etching”. Experience in half¬ 
tone etching will soon teach the proper size 
and shape of high-light dots, and the operator 
should quite readily produce negatives of the 
desired quality by adjusting his high-light 
stop or exposure slightly. In all cases, how¬ 
ever, all deposits of silver should be finally 
solid, and each dot and connection should be 
opaque enough to hold back entirely the strong 
rays of the arc light in printing onto the 
sensitized metal in later manipulations. Too 
much “cutting” can easily ruin a negative by 
weakening the dots and destroying the print 


— 4 - 


V 



Half-tone Negative. 
(Enlarged.) 


ing quality. In different screens, also, while 
the actual sizes of the dots will differ accord¬ 
ing to the screen ruling, the PROPORTIONS 
must remain the same. Half-tone negatives 
for zinc require smaller high-light dots than 
for copper. 

The subject of “color negatives'' will be 
touched on slightly under “Color Etching". 


Many great things in science are simple 
when understood. 

— 5 — 


















































































STRIPPING. 


Stri nng is the process of removing the 
nega five film from its original glass support 
and transfermg it to another, in order to re¬ 
verse the image so it will print correctly, and 
also so several different negatives can be 
grouped upon one piece of glass so as to print 
and etch them all at the same time, thus sav¬ 
ing a great deal of time and labor. 

Coating the Negative. . 

After the original wet plate negative 
comes from the operator, it is allowed to dry 
thoroughly before we proceed to prepare it 
for stripping. The drying can be judged by 
the change of color through the glass side of 
the negative, and can be hastened by use of 
an electric fan or the even application of 
gentle heat. In this state it is merely an 
image of dried sulphide of silver on a thin 
film of collodion, separated from the glass by 
a substratum of albumen. It is therefore 
necessary to give it a more tough film or body 
so that it can be handled in stripping, which 
we do by coating it with rubber solution and 
plain collodion. The original collodion film 
being solvent in alcohol and ether, of which 
it is largely composed, the negative must first 
be protected with a coating of the rubber 
solution, or the fresh collodion poured directly 
onto the original collodion film would dissolve 
it and the image would run together into a 
confused mass. The rubber solution is flowed 
on the negative near one end and tilted to 
cover well with an even coating, draining off 
at the opposite corner of the plate, much in 
the same manner as the original collodion was 
handled in preparation of the negative. The 
rubber dries fairly quickly, but may be hast¬ 
ened by very gentle heat or use of a fan, care 
being taken, of course, not to allow dust or 


- 6 — 



other foreign matter to settle onto it at any 
time. When dry, the rubber still retains a 
sort of sticky feeling or “pull” when rubbed 
with the finger. The plain collodion, known 
as “Stripping Collodion”, is now flowed over 
the rubbered negative in the same manner as 
was done with the rubber solution, but a little 
more care must be used, especially to prevent 
bubbles forming in the collodion bottle by 
allowing the collodion to drain from the neg¬ 
ative directly into the same bottle. Either the 
rubber solution or the collodion can be drained 
off into their respective bottles if a little care 
and good judgment is used, but the most usual 
way, especially on large work, is to drain them 
into other bottles kept for the purpose; then 
when properly thinned down the solution can 
be used again. (The rubber can be thinned 
<for use again by the addition of benzole or 
benzine, bringing it to the proper consistency, 
and the collodion can be thinned by adding 1 
part Denatured Alcohol and 2 parts Ether, to 
the proper consistency. Both should be re- 
flltered before using.) After the negative 
has been flowed with collodion it can be 
placed in a rack to dry, or may be dried quick¬ 
ly (after allowing it to just begin to “set”) 
by gentle !heat, or by touching a corner to a 
flame and allowing it to burn off. Care must 
be taken, of course, not to get the glass too 
hot or it is liable to crack. Also, before the 
stripping collodion was poured on, the nega¬ 
tives must have been almost cool or bubbles 
would be very apt to form on the collodion 
coming in contact with the over-warm plate. 
The negative now has a tough skin-like coat¬ 
ing, which allows stripping and handling 
quite readily. 

Stripping Bath. 

As yet, however, the film adheres to the 
negative glass on account of the albumen 
which was originally used to coat the glass 
on which the negative was made. The albumen 
is dissolved by placing tihe negative in an 
Acetic Acid bath, sometimes called the “soak”, 
for a few minutes. The film, or negative, can 


- 7 — 


now be stripped from the original negative 
glass onto another support where desired. In 
practice, several negatives are generally 
grouped together on a large “flat” or “strip¬ 
per” in order to save time and labor in tbe 
printing ind etching which follows. When 
the negr ives are ready to trim up or cut for 
the acetic acid bath after the collodion is 
thoroughly dry, the trimming is done accord¬ 
ing to the requirements of the job, a sharp 
knife being used for the purpose. Line nega¬ 
tives are cut free-hand around the work, with 
about inch margin around the actual de¬ 
sign, the point of the knife cutting through 
the film to the glass. Square half-tones may 
be also cut free-hand a little larger than the 
required finished plate if no border lines are 
wanted, but if a line is wanted they must be 
cut true and straight to actual size wanted 
or about 1|32 inch smaller to allow for line. 
Ovals are treated in the same manner: if no 
line is wanted, the half-tone negative can be 
cut free-hand, (being sure to cut large enough 
to allow for trimming down true), but for 
“oval with line” an oval “cut-out” form or 
ovaling machine must be used to cut the film 
to size and shape required. When the nega¬ 
tives, after being trimmed, have been placed 
in the acetic acid to soak, we can prepare the 
“stripner” to receive them. The stripper is 
well cleaned and placed still wet on the strip¬ 
ping table in a flat position, so that most of 
the water will remain on the surface. The 
stripping table is usually a raised glass sur¬ 
face (ground glass is best) lighted from the 
under side by electric lights or daylight so 
that the light will reflect up from the white 
surface, which is usually a white paper placed 
beneath for the purpose through the glass top 
of the table to aid in handling and placing the 
negative films. The glass top is best set at a 
slightly sloping angle toward the workman, so 
that any surplus water from the stripping 
operations will flow off instead of stand in 
puddles as on a level suriface. In this case, of 
course, the stripper can be leveled by a loose 


— 8 — 


strip of wood being placed under the near 
edge. 

Transferring and Reversing. 

After the negatives have soaked a few 
minutes, they may be tested for stripping. 
If .they have remained in the “soak” long 
enough, the outer margins or waste films can 
be peeled off with the fingers. This waste 
film may be all cleaned off if desired, es¬ 
pecially if we intend to use the same glass as 
a stripper, and is usually saved as silver 
waste. The acid is now well rinsed off the 
film, and the negative laid face up with one 
edge resting on the far edge of the stripper. 
The stripper must be kept fairly wet with 
water where we intend placing the negative. 
The thin blade of the stripping knife is now 
placed carefully under one corner or edge of 
the film, and with a thumb or fore-finger 
pressing on top, the film is gently stripped 
back far enough to grasp with a thumb 
and fore-finger of each hand. The stripping 
is continued back over the original negative 
glass, until the negative is completely trans¬ 
ferred to thei stripper. The rest of the nega¬ 
tives are stripped in the same manner, being 
sure to reverse them, that is, turn them over 
so that they will be in the same direction as 
the original copy as regards left and right. 
The lens reverses the copy in making the 
negative, so we have to reverse it in stripping 
or the finished etch would print backwards. 
The stripper being wet, the negatives can be 
slid around into suitable position and grouped 
to form a fairly square or rectangular flat, 
so as little metal as possible will be wasted 
by irregularities in fitting. We must, how¬ 
ever, leave at least % inch between the nega¬ 
tives to facilitate separating the finished etch¬ 
ings by cutting between with the saw or 
outer bit. Small groups or single jobs can 
be blotted off at once into position, but large 
groups, or large films which are apt to stretch 
out of shape, are best covered with a sheet 
of wet paper and “squeegeed” off to remove 
most of the surplus water from the films. 


— 9 — 


The paper is now lifted, and small squares of 
clean blotter are used to blot off and dry the 
negatives, starting at the centre of the film 
and working the water out carefully to the 
edge and there blotting it off. All water must 
be removed so that the film will lie smooth 
and flat on the glass, where it will adhere 
spontaneously when thoroughly dry. What 
water remains on the stripper around the 
negatives can be blotted off, the back of the 
glass is wiped clean and dry, and the stripped 
flat of negatives can be put away to dry 
thoroughly for printing or perfect drying can 
be insured by gently warming from the glass 
side. The negatives must be thoroughly dry 
and slightly warm before printing onto the 
sensitized metal. If the negatives are to be 
printed in a hurry after stripping, they can 
be dusted over lightly with French chalk, 
talcum powder, or powdered magnesium 
carbonate. This tends to absorb any slight 
trace of moisture, and prevent the negatives 
sticking to the sensitizer on the metal. 

Difficulties. 

A few difficulties might be encountered 
by the inexperienced stripper, the most 
common of which might be given brief 
mention here, along with preventive sug¬ 
gestions and remedies. In coating the nega¬ 
tive with rubber, the solution must at least 
cover the entire image or design, or the strip¬ 
ping collodion will dissolve the unprotected 
parts and run them. The stripping collodion 
also must cover the whole job, or the part 
covered only with rubber on being stripped 
from the glass support will “shrivel” up into 
a tiny wrinkled mass and consequently be 
parts and ruin them. The stripping collodion 
can be burned off quickly, do not attempt to 
burn off the rubber solution to hasten drying 
the rubber in burning will badly smoke and 
stain the negative, besides bujbbling it into a 
useless mass. Warm the rubbered negative 
very gently if necessary, but it must be allow¬ 
ed to cool well again before flowing on the 


-10— 


collodion. Also, negatives are sometimes 
caused to stick (in stripping) by coating with 
collodion before the rubber is dry: Also by 
too much intensification in the “operating’’. 

Large negatives that are liable to become 
stretched out of true shape or size, especially 
such as maps, architectural work, etc., may 
be flowed twice with collodion, draining at 
opposite corners each time to form an even 
heavy coating. If desired, they can also be 
stripped with the aid of wet papers in the 
‘following manner: place a sheet of wet paper 
onto the soaked negative and strip both paper 
and negative off together; transfer film onto 
another wet paper, and .from that onto the 
stripper or flat. The second wet paper is 
used in order to reverse the film. Squeegee 
down and blot off as usual. Large negatives 
are more apt to stretch out of shape than 
small ones, but in any case too hard pulling 
on the film should be avoided. Replace nega¬ 
tive in the acid bath and soak longer if nec¬ 
essary. If the collodion is flowed on twice, the 
first coating, of course, must be dry before 
the second coating is given. 

Occasionally the film might curl up off 
the glass after being stripped. This is gener¬ 
ally caused by not enough castor oil in the 
collodion, or even an inferior grade might 
sometimes cause this effect. The use of the 
oil in the stripping collodion is to render it 
flexible and enable it to lie smooth and flat 
onto the glass so it will adhere well. The 
remedy is to add more castor oil (or a better 
grade) before using it again. The lifted 
edges of film may be fastened down into place 
with a little thin glue or white of egg, and 
squeegeed again. 


Nothing succeeds like success. 
— 11 — 


METAL-°R!NT1NG 


Zinc INK Printing—For line work on zinc, 
the method in general use is called the “Ink 
Process”, also well known as the “Dragon's 
Blood” Process, which is inexpensive and very 
satisfactory. It is also used considerably on 
course-screen zinc half-tones, especially news- * 
paper work. 

Sensitizer 

The first point to consider is the Sensitiz¬ 
ing Solution, with which we coat the metal to 
enable us to transfer the image (in positive) 
onto its surface preparatory for etching. This 
solution is mixed according to the chosen 
formula, the chemical action of the ingredients 
being chiefly as follows: The water is used 
as a solvent and is also the basic liquid to 
give ciuantity. Bichromate of Ammenium or 
Potassium is the sensitizing agent proper. It 
has the peculiar property of rendering in¬ 
soluble in water an organic matter in mixture 
with it when the mixture has been exposed to 
the action of strong white light for sufficient 
length of time. To furnish the required 
organic matter we use glue and albumen. 
The o-lue also helps the image to develope more 
easilv and cleanly. The ammonia is used 
chiefly as a preservative, although its slight 
chemical action makes the solution a little 
more sensitive and also helps development to 
a small extent. A most simple and conveni¬ 
ent method of mixing the solution is. to first 
measure the required amount of water into 
a graduate, the bichromate into a mortar for 
grinding, and the albumen into the mixing 
bowl. Now add a small quantity of the 
measured water into the bichromate, a small 
quantity to the albumen, and into the re¬ 
mainder of the water in the graduate mix the 
required amount of glue. Mix the glue so¬ 
lution thoroughly, grind the bichromate in the 
mortar well, and beat the albumen (using 


-12— 



a rotarv egg- beater) into a stiff froth. Now 
add the glue solution, beating well to insure 
thorough mixing with the albumen, and then 
the bichromate, again mixing it well in. 
Lastly, the ammonia is added, and the whole 
again beaten well to a frothy mixture. It is 
well to let the solution stand a half hour or 
so let the foam settle before filtering, but 
if desired it can be filtered and used at once. 
The filtering is done through dry absorbent 
cotton, and care should be taken that no 
bubbles form in the bottle, as such bubblies 
break very slowly and cause trouble in coating 
and ->rinting the metal. The solution works 
better, and also slightly faster, after a day or 
two old. This is especially true of Enamels. 

Polishing 

A special pure, smooth-grained zinc is 
used, bought ready polished in large sheets 
of suitable thickness. The most common 
thickness uesd is 16 gauge, although some 18 
gauge (slightly thinner than 16) is used for 
special purposes. The zinc sheets when 
bought are covered with a thin greasy 
substance to protect the metal from the 
oxidizing action of the air until ready for use. 
This coating must be removed by re-polishing, 
wth charcoal or powdered pumice, which 
leaves the metal with just enough grain or 
“tooth" to help hold the sensitizing solution, 
besides cleaning the surface for an even action 
of the etching solution. If charcoal is used, 
it is held so that the cutting or polishing is 
done against its grain; that is, one end of the 
charcoal stick is rubbed down to a rounded 
anele, this angle (the end of the grain) being 
used as the cutting surface. The charcoal is 
usually rubbed across the zinc in long full 
strokes in the direction of the original polish 
of the plate in its manufacture, keeping the 
plate wet under the tap during polishing. 
Occasionally it may be found necessary to first 
polish across the grain of the plate to remove 
fine scratches or other irregularities, and then 
finish up with the grain. If pumice is used. 


-18— 


it is applied to the metal with a pad of heavy 
felt, or a piece of Brussels carpet tacked 
around a small block of wood, rubbing firmly 
against the metal plate and kept slightly wet 
during polishing. After polishing, the plate 
is rinsed well under the tap to remove all 
charcoal, grit, or other foreign matter, and is 
now ready for sensitizing. 

Coating the Metal 

The sensitizing of the metal is done with 
the aid of a “whirler”. A whirler is an 
apparatus in which the plate is fastened and 
made to revolve over a gentle heat to permit 
even and rapid drying of the sensitizer. If 
the ordinary hanging whirler is used it is best 
to place the plate in the whirler before coat¬ 
ing it with the sensitizing solution, but with 
the mechanical whirler the solution must be 
flowed on first. The wet polished surface of 
the plate is flowed over with the sensitizing 
solution, much in the same manner as in 
albuimenizing negative glass. The plate is 
held with the left hand, but resting on the tips 
of the fingers face up, instead of being held 
by the corner. The first flow of solution is 
worked over the entire plate and drained 
off the lower corner, chasing ahead of it the 
surplus water with which the plate was rinsed 
after polishing. A second'flow of the solution 
is given carefully, covering the whole plate 
and draining off as before. The solution drain¬ 
ed off from the first flowing is always thrown 
away, as it contains a great deal of surplus 
water other than that used in its own mixture, 
but the second flowing may be drained back 
into the same bottle if care is taken not to 
allow bubbles to form in the bottle by doing 
so. In this case, the bottle must be tilted so 
as to allow the solution to flow smoothly down 
its side and not cause bubbles. 

The plate is now whirled face down over 
the small heater, and a short distance (6 
inches to 1 foot) above it until the sensitizer 
becomes dry. When dry, the back of the plate 
will feel warm to the hand, but care must be 


-14- 


taken not to over-heat the sensitizer or it 
is apt to become tough and clean development 
of the print later will be impossible. The 
proper speed of whirling depends on the size 
of the plate and also on the thickness or con¬ 
sistency of the solution, and easily determined 
after a little experience. A small plate will 
require faster whirling, usually, than a large, 
as the edges of the small plate would have to 
travel more revolutions in the same time to 
attain the same lineal speed, or centrifugal 
force, as the larger plate. It is best also 
not to whirl the plate face down over an open 
flame; the heater should be covered with a 
piece of old zinc or other metal so as. to 
protect the sensitizer from the direct gases, 
etc., from the flame. After taking the plate 
from the whirler, it is allowed to become cool, 
or almost cool, before printing under the 
negative in the printing frame. The coating, 
whirling and cooling operations must, of 
course, be done in the dark or a weak light 
(or yellow light,) as the coated surface is 
now sensitive to any strong white light. The 
solution, however, is practically insensitive 
until it has become dried. 

Printing 

The “Stripper”, containing the stripped 
negatives, is placed in the printing frame, 
glass to glass, or film side up, and the sensi¬ 
tized zinc is placed in position on same with 
the sensitive coating in contact with the films. 
If preferred, the stripper can be placed on top 
of the coated metal out of the frame entirely, 
and the both “flipped” over together and 
placed into the frame. Care must be taken 
not to tear or “slug” the negatives, especially 
in half-tone work. The padding and back of 
frame are now placed in position on top of 
the metal, and the frame is tightened down 
well to insure perfect contact. No grit or dirt 
of any kind must be allowed to come between 
the two glasses or the stripper and metal, 
as a very small particle will sometimes be 
sufficient to cause uneven pressure and crack 


—15— 


the glass, either the heavy frame glass or the 
stripper. It is well on large work to bend the 
metal slightly the sensitized side being the 
concave, so that the plate will rest jnly on 
its two edges until the pressure of the frame 
brings the centre into even contact, thus 
avoiding danger of slugging. The printing 
can now be carried on in the sun (in summer) 



or by arc light. The frame is placed in posi¬ 
tion and the sensitized metal exposed through 
the negatives to the light for the proper length 


16 - 
























of time, according to the sensitizer formula 
used, the strength of light, and the distance 
of the frame form the light. Sunlight, of 
course, gives a good even light over the entire 
frame r^ardless of size but its strength 
varies so from day to day, as well as accord¬ 
ing to the time of day,'while the arc light is 
more uniform and we can feel more certain of 
results. The frame, however, should be placed 
at a distance from the light at least equal 
to the diagonal of the plate being printed. 
This is done to get even lighting over the 
plate, and if the frame is too close, while it 
allows of shorter exposure over the central 
part of the plate, the corners will be under¬ 
exposed and will not likely hold well in de¬ 
veloping up the print. A good rule to remem¬ 
ber is: the strength of light decrease^ as the 
square of the distance increases; thus: a print 
remr'^«o- i minute exposure at 1 foot distance 
would require 4 minutes (2x2) at 2 feet 
distance, or 9 minutes (3x3) at 3 feet. 

Developing 

After- the exposure has been completed, 
the printing frame is again turned face down 
and opened, the back removed, and the plate 
taken out to the rolling-up table. With a 
large Composition roller of good quality, or 
a fine nap lithographic roller, the sensitized 
coating of the plate is rolled up with a thin 
even film of Etching Ink. This is a slow- 
drying ink made especially for the purpose, 
and has adhesive qualities which permit any 
fine powder sticking to it quite readily. A 
little experience is required to know just what 
amount of ink should be used. Over-inking 
should be avoided, as this will tend to thicken 
the lines of the print and also cause it to not 
develop out well. The best results are gen¬ 
erally obtained when the ink is just heavy 
enough to show from a deep olive color to 
black. The rolling-up, as well as the sensi¬ 
tizing, should not be done in a strong light. 
After rolling-up, however, the print is practi¬ 
cally light-proof, and can now be developed 


—17— 


up in stronger light without danger. The 
inked brint is developed under a tap or in a 
tray of water, aided by lightly swabbing over 
with a tuft of soft clean cotton. The water 
can be warmed considerably if necessary to 
help development, or a few drops of ammonia 
may be added to the water. As explained 
above, the strong light acting on the ammon¬ 
ium bichromate in mixture with the glue and 
albumen renders the mixture insoluble in 
water. In printing, the action of the light 
through the clear parts lines etc. of the 
negatives has rendered those portioris in¬ 
soluble in water while the parts protected 
bv the dense black background of the nega¬ 
tives were not hardened by the action of the 
lip-ht an$ are therefore soft and easily wash¬ 
ed away under the tap during development, 
carrying with them their coating of etching 
ink. After the print is thoroughly developed 
and rinsed clean of loose ink, it is dried by 
patting gently with a soft moist chamois fol¬ 
lowed by slightly warming over the stove. In 
us’ in ' v t^e chamo’s. the print must be patted 
carefully, not rubbed, or the result will be a 
dirty, smudgy print. 

Topping 

The -mint is now touched up, or spotted, 
for defects, using etching ink thinned very 
slightly with turpentine, painting up with a 
small brush all breaks and defects in the ink- 
printed design. A “bridge” or “rest” is used 
to raise the hand off the work while painting 
up. so as to not smudge the print. The back¬ 
ground, called “dead-metal”, is also now paint¬ 
ed up roughly to about l A inch from the lines 
of the print. This painting up of the dead- 
metal effects a great saving of acid as well 
as lessening the fumes given off. It also 
helps considerably in powdering evenly and 
holding fine lines during etching. When all 
painting and touching up is completed, the 
plate is dipped into a box or tray of fine 
resinous powder known as “Topping Powder”, 
rubbed over carefully with a tuft of cotton 


-18- 


so that the powder will adhere well and 
cleanly to the ink, and brushed well with a 
soft broad brush to clean the bare metal of 
topping powder leaving a good coating of the 
powder sticking to the inky lines of the design. 
It is best to warm the plate slight!^ before 
topping, which tends to soften the ink just 
enough to hold the powder well and allows 
better cleaning of the clear spaces. The plate 
is heated gently after powdering until the 
powder changes from a gray color to black, 
showing that it has melted and combined with 
the ink design, forming, when cooled, an acid- 
resist top ready for the first “bite” in the 
etching solution. The print must not be heat¬ 
ed too strongly, or the lines will spread and 
thicken, making the whole design heavy and 
smudgy in comparison with the copy. Zinc, 
when heated to an excessive degree, will easily 
melt, and in any case will cause the metal 
to weaken and become grainy or brittle. Just 
enough heat should be applied to darken the 
topping powder and fix it into the ink design, 
being sure however that it actually melts 
together so as to make a solid impervious 
“top”, yet without heating enough to spread. 

While the print is still hot, it is stood 
against a wall or other support, and the back 
painted over with asphaltum or heavy shellac 
to protect the back of plate from the corroding 
action of the acid during etching. Asphaltum 
is most commonly used, as it is much cheaper 
and more acid-proof than shellac. When cool, 
the plate is ready for the etch. 


Zinc ENAMEL POINTING—The Zinc 
Enamel process is used in some workrooms to 
a great extent, while in others it is not used 
for any work whatever. It is used consider¬ 
ably in half-tone work on zinc, especially when 
85 line screen or finer is used on zinc, and also 
in some fine line work, but is not always so 
certain of holding well as in the Ink method. 
It does not require rolling up with etching 
ink, however, and usually works cleaner on 


-19— 



fine work; so where great depth or much etch¬ 
ing are not required it is very practical. 

The Zinc is polished and prepared the 
same as for use with the Zinc Sensitizing 
Solution and Ink process, rinsing the plate 
under the tap afterwards to remove all grit 
and forei 0 "- 1 matter. The wet polished surface 
of the metal is flowed over twice, as before, 
draining the first flow off and the second flow 
back into the bottle if desired; but in this case 
Zinc Enamel is used instead of Sensitizing 
Solution, which latter is much thinner and 
more free-flowing that the Enamel. The 
Enamel, therefore, must be flowed carefully 
and evenly and more judgment must be used 
in the whirling. 

After the enamel-coated zinc has been 
whirled dry and cooled slightly, it is printed 
under the negative in the printing frame just 
as was done with the ink process. Usually, 
however, the enamel requires longer print¬ 
ing time than the thin sensitizer. 


Showing how 

Thickness of Tnamei 
dnd D/s fence from L/gfif 
con fro/s the Print. 


Z -'/ (MV'S 

L/6HT 





The exposed plate is removed from the 
frame and developed under the tap at once, 
without any rolling up. A spray nozzle on 
the tap makes an excellent “squirter” and aids 
materially in the clean development of the 
print. If necessary, after spraying under the 
tap, the plate may be laid in a tray of warm 
or fairly hot water to develop out thoroughly. 
This dissolves away the fine fuzzy connections 


—20— 






which sometimes tend to fill up the print, 
especially noticeable on half-tones, and cause 
a dirty appearance in the finished work. The 
print can be examined well by flowing over it 
a dye solution, which colors the enamel on 
the metal and washes away easily from the 
cleared metal, thus showing the print clearly 
and perfectly as it is on the metal. The dye 
has no function whatever in the actual de¬ 
veloping of the print, only serving to help 
jude-e the work. Any holes, dirt, or other 
defeats in the print may now be seen dis¬ 
tinctly, and if too bad it can be scrubbed off 
and be re-printed. If the print is satisfactory, 
it is well rinsed and “hardened” to better 
withstand the action of the acid in the etching 
process. The hardening is done best by soak¬ 
ing the print for about five minutes in a tray 
of Enamel Hardening Solution (see formula), 
allo^'no- r*]f»nty of time for the solution to act 
through to the metal. The print is then well 
rinsed off under a tap, and dried over the 
stove very carefully in the following manner. 

In drying, the plate is held by one comer 
with a Pair of pliers the opposite corner be¬ 
ing held over the s f ove and raised slightly 
so as to tilt the plate the surplus water 
running to the opposite corner. The top 
comer is heated slowly an4 es it dries the 
plate is slowlv mov°d forward, allowin'* the 
beat to gradually and steadily force the water 
back to the lower corner. The water or 
moisture must not be allowed to form in a 
drop or “lake” on the plate as the print dries 
around it, as it is almost sure to leave a 
dark uneven spot and spoiling an otherwise 
good print. The heating is continued after 
drying, the dye burning off, then the print 
begins to darken until it becomes of a very 
dark brown color over the entire plate, in an 
even color of light and shade. The plate Is 
quickly removed from the stove and laid face 
up on a stone or iron slab to cool gradually. 
Never plunge a hot enamel plate under a tap 
to cool it quickly, as this practice will cool 
the enamel too suddenly and weaken it, and 


-21- 


also will render the metal tough and hard to 
work. When cool, the plates is touched up 
with “staging ink” and burned m (tested by 
a sizzling when touched on the back of plate 
with a wet finger), and then painted on the 
back with a good coat of shellac. When it 
has become cool again, the plate is ready for 


etching. 

Copper ENAMEL Printing—Copper En¬ 
amel Printing is handled precisely the same 
as Zinc Enamel, excepting, of course the 
print is made on copper instead of on zinc, 
and Copper Enamel is used as the sensitizing 
agent and resist top instead of zinc Enamel. 
Also, usually no hardener is used after de¬ 
veloping the print. Some workers use .it, but 
it has a tendency toward brittleness and 
working with less smoothness. Few addition¬ 
al instructions are necessary, but the follow¬ 
ing will be beneficial. 

In polishing copper some workers prefer 
to rub in a circular motion or in small rings 
over the whole plate, especially if using char¬ 
coal. A good soft grade of charcoal should 
also be chosen for this purpose. The direction 
of polishing may be left to the choice of the 
workman as either the circular or longitudi¬ 
nal motion will give equally good results so 
long as a good even polish is obtained. 

The copper enamel should be burned in 
to a rich chocolate brown. After laying on 
the cooling slab it still gradually darkens 
slightly while cooling, as the copper holds 
heat for a considerable time. The highlights 
also, on a very good print, will then turn to 
a silvery color or slight pinkish tint during 
cooling. Forced cooling is bad for the en¬ 
amel and copper, and should be avoided. 

The copper print is usually backed with 
very thin shellac, thinner than used for zinc 
although paraffin wax can be used while the 
plate is just warm but is not so good. Par¬ 
affin is very apt to cause trouble by getting on 
the face of the plate during burning in the 
staging, etc., thereby causing bad spots in 


—22- 


the etching. After spotting, or touching up 
with “staging ink”, the plate is ready for 
cleaning preparatory to etching. (Copper 
Etching.) 


A Few Enamel Difficulties and Causes. 

(Remedies suggest themselves.) 

Thin spots thin enamel, etc. = poor flowing 
or too fast whirling. 

Thin spot in centre usually suggests too fast 
whirling. 

Thin spot near corner suggests poor flowing 
or too sudden draining of first flowing, 
leaving some water mix with enamel. 

Soft enamel (develops off)—over entire plate, 
= underexposure in printing, or too 
thick enamel. 

Soft enamel (develops off—at corners only,= 
wnirler too low (too close to whirler 
heater) or frame too close to light in 
printing; or enamel heavy at corners 

due to improper whirling. 

Solid or filled-up shadows (in half-tone), = 
over-exposure, thick enamel, frame too 
close to light, weak negative, lack of 
contact, etc. 

Dirt spots, ^usually dirty enamel (or dye): 
Re-filter or mix new. 

Enamel lifting (during etch), = thin enamel, 
insufficient polishing, first flow drained 
off to suddenly, not properly rinsing off 
before flowing with enamel, too strong 
scum-clearing solution, too acid, or not 
rinsing clearing solution off well. Usu¬ 
ally not thoroughly clean working 
somewhere. Seldom a really good ex¬ 
cuse for it. 


,,For his henrt was in his work, and tin* heart sriveth 
grace unto every ax’t. —Longfellow. 



Z'.NC ETCHING 


Tub etching is the most suitable method 
of etching zinc by the inexperienced workman, 
as by this method the progress of the work 
and the action of the acid on the metal can be 
watched and understood well. It is the method 
in most general use, although etching ma¬ 
chines are becoming more popular all the time 
on account of their speed and clean working 
qualities when properly handled. But the 
etching action cannot be so well noticed, yet 
the principal is entirely the same as in the 
rocking tub etching, so at present we will 
oonsider only the latter method. 

The Acid Bath 

The principal of zinc etching is based on 
the fact that nitric acid etches or dissolves 
zinc, and the design on the zinc plate is com¬ 
posed of acid-proof material, being a com¬ 
bination of greasy etching ink and resinous 
topping powder in making the print. The 
bare zinc, which is free from such acid-proof 
protection, is acted upon chemically and dis¬ 
solved by the acid solution, the plate being 
rocked back and forth in a large tray-like 
tub containing the acid solution. 

The strength of acid solution and the time 
of etching is governed by the character of the 
work. The acid for the first “bite” is gen¬ 
erally composed of about 1 part Nitric Acid 
(Commercial, 38 per cent) to 12 or 14 parts 
water, and about three minutes will usually 
be found sufficient time for this etch under 
these conditions. Just enough etching so¬ 
lution should be used to flow over the nlate 
well and evenly when the tub is rocked, allow¬ 
ing- the plate to be exposed to the air as the 
acid washes to either end of the tub. The 
fastest and smoothest etching is obtained 
during this time the chemical action of the 
acid in conjunction with the oxygen from the 
air oxidizing or corroding the zinc with a fine 


— 24 — 



satin finished surface. As the plate is rock¬ 
ed back and forth, a fine scum of tiny 
bubbles forms on its surface. This must 
be carefully brushed off from time to time 
with a flat bristle brush, leaving the etched 
surface bright and clean. It is important to 
keep the surface smooth and bright without 
brushing it enough to cause “undercutting” or 
loss of fine details. The etching is watched 
carefully, the tub kept rocking continuously, 
and the etching surface brushed smooth and 
clean as the oxide forms, thus keeping a 
smooth “bottom”, as the clear metal surface 
is called. Practice alone will show the right 
amount of brushing required. At first the 
acid can etch in only one direction, that is 
downwards, but soon a fine bright edge ap¬ 
pears along the sides of the lines and if the 
etching is then carried much farther it will 
begin to “under-cut” or work under the'inked 
surfaces. It can easily be carried too Tar, 
but this should be skillfully avoided. On fine 
line work, of course, the etching on the first 
bite must be stopped sooner than on coarse 
work. When the etching has been carried far 
enough to allow just catching with the finger 
nail slightly when tested on the lines or dead- 
metal, there will be nlenty of depth for the 
first powdering of Dragon’s Blood powder. 
The plate is now removed from the acid and 
quickly rinsed under the,tap. then can be dried 
with the chamois and warmed slightly over 
the stove. 

4-Way Powdering 

‘Dragon’s Blood” is a general trade name 
applied to an acid-proof resinous powder used 
in zinc etching to protect the sides of the 
lines, etc., from further etching while the 
background is being etched away to a suitable 
printing depth for the printing press. 

The plate, while just warm and perfectly 
dry, is now dipped into the drawer or tray of 
Dragon’s Blood, picking up a good quantity 
of the powder at one edge of the plate and 
sliding it, by tilting, to the opposite edge and 
back into the tray. What powder remains on 


— 25 — 


the plate is now brushed carefully in one di¬ 
rection toward where the powder was slid off 
using a broad soft hair brush (fitch hair or 
thick camel hair), holding the brush at an 
angle of about 45 degrees to the plate, press¬ 
ing firmly enough to bank the powder against 
the sides of the fines. Those etched sides 
of the lines, (the sides facing one edge of the 
nlate only), may be examined carefully with 
a magnifying glass or a linen tester if desired 
to see that no small breaks or nin holes are 
present in the powder, as the smallest pin hole 
will be large enough to admit the acid solution 
to the metal line and cause a ragged or broken 
line in the finished work. With practice and 
care it is seldom necessary to examine so 
closely after powdering, as when a skilled 
workman becomes a^ustomed to the work he 
will have a reasonable amount of confidence 
in the security of his powdering. The main 
noint is, we must have a solid even line of 
Dragon's Blood powder pressed against one 
side of all lines, dots, etc., c.f the design, from 
powdering in one direction, and at the same 
time have the etched sunken surface of the 
metal brushed clean and free from powder. 
When this is done, the plate is carefully 
placed on the stove so as to not jar the powder 
from its place, and heated just enough to melt 
the Dragon's Blood against the lines, chang¬ 
ing it from a bright red color to a deep brown 
or almost black. This requires more heating 
than to fix the topping powder in preparing 
the print. The plate is then rolled over a wet 
roller, made for the purpose, to partially cool, 
wiped dry on the back, and after noting that 
the front or printing surface is also thorough¬ 
ly dry and just very slightly warm, it is ready 
for the second direction of powdering. The 
plate is dipped into the Dragon's Blood and 
v brushed over in one direction exactly as be¬ 
fore, excepting this time in a different direc¬ 
tion. Ajfter this powdering is burned in and 
partially cooled as before, the third and then 
the fourth powderings are given, each pow¬ 
dering being done in a different direction, or 


started at a different edge of the plate. Any 
order of powdering may be used, but it is best 
to powder the same directions always in the 
same order, such as: left, right, top, bottom. 
If the plate is one in which all sides of the 
design are nearly alike so that it is difficult 
to remember which sides have been powdered 
and which not, then one edge must be marked 
“top” or some other distinguishing mark, or 
one is apt to powder two or more sides twice 
and the other sides will be missed entirely, 
giving no protection to those sides of the lines. 
After the four-way powdering has been com¬ 
pleted, each powdering being burned in before 
the next is given, the plate is ready for the 
second bite in the etching tub. 

Some etchers prefer, especially on fine 
work, to give a fifth powdering; that is, pow¬ 
der four ways as usual, then turn the plate 
and re-powder in the first direction, thus giv¬ 
ing the first powdering an extra coating for 
safety. This is done, however, only after the 
first bite, but is left to the choice of the 
etcher whether he wishes to follow it at all 
or not. 

Successive “Bites”* 

The second bite may be given in the same 
acid solution that was used for the first bite, 
without increasing its strength, but a little 
acid may be added if preferred. The plate is 
rocked and brushed occasionally as in the first 
bite, taking care to keep the bottom of the 
etch clean and free from heavy scum collec¬ 
tion without too much or too hard brushing 
Let a thin layer of scum form on the surface, 
then brush lightly over the plate to remove 
it, repeating the operation only when neces¬ 
sary to keep the etch clean. When the bottom 
edges of the lines begin to show bright again, 
the etching must be watched more carefully 
again, and when it appears that it cannot be 
safely taken any farther, it is removed and 
dried as before, and powdered for the next 
bite. The operation is repeated, adding a little 
more acid for each bite, bringing the strength 
up to from two to three parts acid to 12 parts 


-27— 


water. Usually about four bites (three pow- 
derings) are sufficient to obtain a good print¬ 
ing depth, or until the plate is etched about 
one third or half way through its thickness. 
If necessary, however, an extra bite or two 
may be given, as is often the case on fine 
work, powdering four ways after each bite, 
givir 10, nrotection to the sides of the lines for 
the following bite. Care must be taken dur¬ 
ing the wlhiole etching to keep the bottom 
brushed free from scum as it forms, not using 
too hard or harsh brushing, of course, and also 
to bank the Dragon’s Blood nowder well 
against the lines, melting it well in to form 
a clean even acid-resist, and at the same time 
keeping the bottom brushed clean and free 
from the powder, r 0hie fine details must be 
watched carefully that they do not “under¬ 
cut” or even lose entirely. Work in which 
the lines are close together does not, as a 
rule, require as much depth as where the 
lines are far apart, as t!he close lines act as 
support for the printing press rollers in 
printing from the cut, thus preventing the 
paper from “smudging” on the bottom of tne 
etching. 

It is well to note that each successive 
powdering (that is, four ways after each bite) 



A. firtf PvM/(fcr//Q,-(after- f/nf in/t} 




AruSug Surface v 


^ A-ZAo. «/ P/e fa 


C. 7W/W^. M 

Illustrations cJtowwq SrusA Amg/e % 

<tur,/Q successive pondun/Qs. 


is best done with the brush held more straight 
and firm than for previous bites. As the de- 


-8 - 






sign is etched deeper and deeper, the powder 
must be banked against the lines more firmly 
and less sloping along the etched edges in 
order to avoid a broad rough “shoulder” on 
the finished work. Too mudhi shoulder on an 
etching makes poor and difficult printing, as 
well as poor electrotyping if the plate is to be 
electrotyped. 

Cleaning the Plate. 

When sufficient depth is obtained, the 
plate is heated quite hot and immediately 
flowed over with a strong solution of ordinary 
lye or notash. This sudden contact of the lye 
and the hot plate lifts the ink and powder 
coating, and with the aid of a stiff brush the 
plate is scrubbed clean and bright. The lye 
is then thoroughly rinsed off under the tap, 
and a solution of old perchloride of iron (used 
in cooper etching), or copper sulphate, is 
poured over the plate, the chemical action 
which takes place immediately giving to the 
z ; r~ a dull black surface, which helps mate¬ 
rially in routing and finishing up the plate. 
The ton or printing surface of the design is 
now rubbed over with a stick of charcoal, 
which leaves the details of the design stand¬ 
ing out in bright relief lines on a dead black 
background. After rinsing and drying, tfhe 
plate is ready to be routed, blocked and fin¬ 
ished for the printer. 

“Cleaning Bite”. 

Some etchers will occasionally remove 
any excess shoulder from the etched plate 
by re-topping and brushing briskly in the 
etching tub a short time. This “cleaning 
bite” is very seldom used, and should not be 
necessary, but if desired it can be done by 
rolling up the cleaned and dried etching with 
etching ink, topping powder (blowing off the 
surplus powder), melting in the top as usual 
except that an extra heavy top is given 
and it is allowed to melt down the sides of 
the lines; after the shoulder has been re¬ 
moved in the etching tub, the plate is clean¬ 
ed, blackened, and charcoaled as usual. 


—2U— 




Half-tones on zinc are usually given only 
one good bite, without any four-ways powder¬ 
ing, but course screen work such as 60 or 65 
lines to the inch, or even 85 lines, may be 
given one four-way powdering and an extra 
bite if handled carefully. In powdering a 
half-tone zinc plate, however, the etcher 
must use skifll and discretion against rough 
or uneven powdering, or a rough smudgy 
half-tone will be the result. 

If the plate contains half-tones or fine 
“Ben Day” tints, in combination with the 
line work, the half-tones or tints, etc., should 
be painted up solid with staging or etching 
ink after the first or second bite. This pro¬ 
tects these parts, which are really finished, 
while the lines are being etched to their 
proper depth. 

Zinc Graining. 

Zinc Graining is one method of produc¬ 
ing a tint on zinc, and is done entirely by 
the etcher. The method is used to some ex¬ 
tent yet, although not so much as in the past, 
especially since the advent of the “Ben Day” 
process of laying tints and shades on the 
metal. The method of graining, however, will 
be very briefly explained for those desiring 
to know.—A large tall tight box stands up- 
r:ght, containing a small quantity of Dragor/s 
Blood powder at the bottom. Also near the 
bottom is a small hole to admit the nozzle 
of a bellows, and a short distance above is a 
sliding rack on which the plate may be slid 
in and out. With a sudden blast of air from 
the bellows through the hole in the box, a 
cloud of the powder is raised to the top part 
and allowed to settle, filling the box with a 
very fine dust of powder which is so fine that 
it settles very slowly and evenly. After 
stirring the powder up well and allowing it 
to settle somewhat, the plate to be grained 
is slid into the box, face up, by means of 
the sliding rack, and the Dragon’s Blood 
powder, in settling, covers the plate with a 
fine even grain. The plate is withdrawn from 
the box and burned in over the stove to melt 


-30— 





the powder onto the nlate. T f t>e grnin doe? 
not seem to be dark or strong enough to 
produce the desired tint, the same operation 
can be repeated until it is satisfactory, lay¬ 
ing one grain over the top of the other. 
When burned in we now have the plate cover¬ 
ed with an even grain tint of acid-resisting 
Dragon’s Blood, which can now be etched by 
the usual zinc method. If only cer f ain parts 
of a design are to be grained, of course, the 
other parts of the plate (wherever no grain¬ 
ing is wanted) must be painted over with 
gum gamboge, ooaque, or other water-color 
pigment before the grain is laid, as in the 
4 ‘Ben Day” process. (See “Ben Day” Work.) 
Another form of graining box, preferred by 
many, is one which is hung at its centre in 
such a manner that it can be revolved rapidly. 
This box has no bellows opening as in the 
stationary, type, as the powder is stirred up 
by swinging the whole box over rapidly 
several times, then allowing it to settle. The 
plate is slid in and completed in the same 
manner, as previously explained. 

Re-Topping. 

In using Enamel for Zinc Etching, it is 
sometime difficult to get good depth without 
the enamel resist lifting or breaking through 
in - 1 ' > '’es, especially on line work where con¬ 
siderable depth is required. If the enamel is 
seen to be ready to break through, or looks 
uncertain, after a fair depth is reached, the 
r>late can be rolled up with etching ink (using 
a hard composition roller and plenty of ink), 
powdered over well with Dragon’s Blood or 
Tonning Powder, the loose powder blown off 
clean, and the “top” burned in. This will 
give a new resist top composed of ink and 
powder as in the ink process, and further 
etching can be carried on with safety. 

“Stop-out”, or color zinc plates, are etched 
precisely the same as the ordinary zinc prints. 
’The prints, o.f course, are “stopped-out”, 
scratched, painted up, Ben Dayed, etc., as 
required in preparation for the etching. 


COPPER ETCHING 


The Printing of the image on the copper 
plate has been described under the heading 
of ‘‘Metal-Printing”, so we can begin here 
with the print, developed, burned-in, etc., 
ready for etching. It is presumed, of course, 
that the back of the plate has been shellaced 
for its protection as usual, and also any 
defects on the print spotted up and burned in. 

Copper Etching usually refers to half¬ 
tone work, but where line work is etched on 
copper, it is handled the same as on zinc. After 
the first bite or “flat etch”, (excepting the 
difference in the etching solution used), 
powdering four ways wih Dragon’s Blood 
powder, etc., until the proper depth is obtain¬ 
ed. While Conner Half-tone etching is based 
on the same principal to some extent ^s zinc 
etching, i. e., the metal is etched or dissolved 
away by chemical action, yet the work is 
entirely different. In zinc etching the main 
object in view is “depth”, while in copper 
etching we must work for “color” or “tone”. 

Clearing 


The first difficulty usually encountered 
in copper half-tone etching after the print 
is obtained is “scum”. This may be described 
briefly as a very thin film or haze of enamel 
adhering over the “open” dots of the print, 
and must be removed or “cleared” before 
starting the etch, or a ruined plate will be the 
result. Scum can generally be removed by 
v 11 ^ °I clearing solutions given in the 
list of formulas, such as the permanganate 
or salt and acid solutions, rubbing over the 
plate carefully with a small tuft of cotton, 
sometimes the aid of bicarbonate of soda in 
conjunction with the clearing solution being 
necessary. A very weak solution (not over 
* r>e ] r c f. n V of potassium cyanide may be 
found satisfactory, but this must be used with 
discretion or the enamel print is likelv to be 
weakened. Care must also be used with the 







sod,a, as too severe rubbing is apt to grind the 
enamel thin and cause it to break through in 
etching. If the scum appears obstinate and 
does not yield readily to the clearing solution 
it is usually safest and best to polish off the 
print and repeat the operation. After the 
scum has been removed so that the copper 
shows bright and clean in the open dots, 
especially in the shadows, the plate is well 
rinsed and is now ready for the “flat etch”. 

Flat Etch. 

The etching solution used for copper is 
Perchloride of Iron (or Iron Chloride), and 
should test by hydrometer between 35 and 
40 Baume. The temperature of the solution 
should be satisfactory, or normal, in the 
average workroom, but if very cold its action 
is very slow. For very rapid action the solu¬ 
tion can be heated up to as high as 100 deg. 
F. The most satisfactory method of etching, 
especially on fine screen work, is face down¬ 
wards in a still bath of the iron solution. 
Nothing is gained in half-tone work by rock¬ 
ing the bath (as in zinc etching) if the plate 
is face downwards. On the other hand, if the 
plate is face upwards rocking will generally 
increase contrast somewhat, but the depth 
is greatly lessened. Again, still-etching tace 
upwards produces a flat or gray effect, and 
is sometimes used in color work, but again 
loses in depth. Depth on half-tones, while 
sometimes looked upon as a secondary matter, 
must be considered important at least, as a 
half-tone with excellent color will often print 
up very unsatisfactorily on account of being 
shallow. However, if properly handled during 
the etching processes, it sholud have good 
printing qualities. So at present we will 
consider the first mentioned method, the one 
in general and most satisfactory use for clean 
soft printing results. The plate is suspend¬ 
ed in the iron solution about X A inch from the 
bottom of the tray by means of two small 
blocks of wood placed on opposite sides of 
the nlate, the edges of the plate being insert¬ 
ed in shallow grooves sawed in the blocks 


about % inch from the end. In starting the 
“flat etch”, the plate, after being cleared of 
scum and well rinsed, is dipped face up into 
the iron solution and brushed lightly all over 
with the iron, using a broad soft camel hair 
brush or a good sized tuft of cotton, in order 
to insure an even start in the etching tray. 
The two blocks are now placed on the opposite 
■edges in the manner just described, and the 
plate “slid” edgewise face down into the iron. 
Care must be taken to slide the plate smoothly 
into the solution, and not to merely lower it 
straight down flat, thus avoiding air bubbles 
on the etching surface. The time or duration 
of the “flat etch” is governed principally by 
the pitch, or coarseness, of screen used and 
b'’ the character of the print. The shadow 
dots in particular must be judged, the smaller 
shadow dots permitting a longer etch than 
more open ones, not over-looking, however, that 
the middle tones must also be dark enough to 
stand the desired etch without losing color 
It is desirable, as a rule, providing our 
negative is correct, to obtain a fairly strong 
print on the metal and allow for a corre¬ 
spondingly long flat etch, thus procuring good 
dentil and clean printing qualities. As a gen¬ 
eral rule, for 133 screen (the most commonly 
used), the flat etch should not be less than 
10 minutes with the iron solution at normal 
condition, and the time might be increased in 
some cases to 13 or even 15 minutes. Careful 
judgment should be used, however, before 
attempting 15 minutes for 133 screen. A fair 
average for 85 screen might be struck at 
about 18 or 20 minutes. Finer screens, like¬ 
wise will require shorter etch, but the color 
or “strength” of the print is a great con¬ 
trolling factor in any case. It is also im¬ 
portant to move the plate occasionally in the 
solution, so that fresh iron may reach the 
etching surface from time to time, thus 
etching cleaner, deeper, and smoother, and 
esnecially avoiding spots from any bubbles 
which might interfere with the chemical 
action. 

When the time of flat etch has expired, 


—84— 


the plate is withdrawn from the solution, 
rinsed well under the tap, dried with the 
dampened chamois and then over the stove. 
A fine stiff cleaning brush is now used to 
“dry brush” the etched surface, brushing well 
in two or more directions and reaching all 
parts of the work. The reason for the brush¬ 
ing is this:—in the process of flat etching, 
the iron solution, besides etching depth, works 
slightly under the edges of enamel, leaving a 
very small over-hanging ledge of enamel, or 
“ca"”, around each dot. Thus the apparent 
dot is larger than the actual dot of metal or 
printing surface. Dry brushing breaks away 
these tiny caps, showing the dots (and con- 
seauently the tones) in their true values. 
After dry brushing, the plate is “chalked up” 
with magnesium carbonate (in cake or powder¬ 
ed form), rubbing the magnesia well into the 
etched dots and off the enamel surface quite 
clean with the fingers or palm of the hand. 
Care must be taken not to scratch the enamel 
by allowing any grit to be rubbed in with the 
magnesia. We now have an etched image 
on the copper plate, in half-tone, resembling 
fairly well in light and shade the original 
photograph or “copy”, excepting that it will 
appear somewhat “flat” or lacking in brillian¬ 
cy as compared with the copy, the high-lights 
especially appearing darker than the original. 

Staging 

The plate must now be judged for color, 
or tone, comparing it with the original copy. 
The shadows and darker tones should be 
found to match the copy quite well, and these 
parts must be protected or held from further 
etching while the rest of the work is lightened 
to correspond with the lighter tones of the 
copy. This is done by what is called “staging” 
and “crayoning”. Staging is used on parts 
where the copy calls for hard sharp-cut 
euges of tone and where the tones are to be 
feld ; ust as they are on the flat etch. This 
is done by painting over those parts with 
“staging ink”, using a good red sable or 
camel hair staging brush (a round, full well 


^35— 


pointed artists’ brush, commonly known as 
a “rigger”), painting in solidly and smooth!'.y 
all parts to be held absolutely protected from 
any etching action when the plate is again 
placed into the iron solution. Crayoning is 
used where small soft details are to be held, 
or where fluffy uneven masses are reouired 
to retain their color softly blended, or 
practically wherever tones are to be held to 
a greater or less extent, depending on the 
manipulation of the crayon, to retain the soft 
delicate blending of the cony. Carefully 
trained judgment and experience, however, 
are necessary to enable the workman to know 
how best to handle each subject, just where 
to stage, where to crayon, and iust how best 
to handle the crayon on the different parts 
of the work in hand. (The crayon used is a 
black greasy lithographic crayon, in the form 
of paper-wound pencils or in heavy hexagonal 
sticks (paper covered), or a good grade china 
marking pencil (paper-wound) will be found 
practically the same article »s the htho 
crayon or pencil. It is impossible to explain 
exact rules to govern all classes of wot*k. as 
each individual subiect must be judged and 
handled by the workman himself, keeping in 
mind in connection with the staging and 
crayoning, the manipulations following, such 
as *he “short etch” and re-etching”. Right 
here is the point that to a very marked 
degree classes a half-tone etcher as a good 
or poor grade of workman. However, a few 
general hints wdll serve as a guide. 

In the average portrait work very little, 
if any, staging is used, crayoning usually 
taking care of the necessary tone protection. 
We can usually start by crayoning the eye- 
brews, drawing the litho pencil in a clean 
sweep from the end of the eyebrow nearest 
the nose toward the outer end. Enough 
pressure must be applied on the crayon to 
force it well into the open dots of the plate, 
thus giving the eyebrow tones strong pro¬ 
tection from etching yet retaining their 
original hairy softness. Next, the lower edges 


—36— 


of the eyelids, from the nose outward in the 
same manner as the eyebrows except that 
finer lining must be used. A small hard dot 
of crayon will usually be found necessary in 
the corner of the eye directly against the 
nose, at the inner end of the lid line just 
crayoned. The entire iris (or colored portion) 
of the eye must be crayoned heavily and 
smoothly, working the pencil in a small 
circular motion. Occasionally, but not always, 
a slight touch of the crayon on the under 
part of the eye will improve color. The nose 
next demands attention, but very seldom any 
work will be necessary here except a small 
hard touch of crayon on each nostril, and 
occasionally a light touch around the outer 
curved portion of the nose on the shadow side 
of the face. In crayoning the mouth, only 
the under side of the upper lip is crayoned, 
usually, as well as definite indentations at 
both ends of the lips. Care must be taken, 
however, in crayoning the lips, holding their 
proper shape and expression, and the little 
indentations marking their ends are very 
important to hold expression. Very rarely, 
also, a slight touch under the chin to hold 
the suggestion of shadow is good, but here 
again e-ood judgment must be the deciding 
factor, depending on the copy always. In 
crayoning the hair the workman must notice 
carefully the trend or general direction of 
the waves of the_hair, also the lighting on it. 
Work the crayon in the same general di¬ 
rection, working in the shadows and darker 
portions, not attempting to strengthen any 
individual hairs, or even suggestions of such, 
but working more in masses of tone,, light and 
shade. All spotty or patchy effects must be 
avoided, crayoning in broad full effects parti¬ 
cularly in the lower or deeper curves of the 
hair masses, allowing the lighter tones, 
especially the highest lights, to remain 
■freely exposed for more etching. Strong 
crayoning is usually more satisfactory on the 
hair than too weak, so there is little danger 
of over-crayoning. In case of a dark back- 


ground, darker than the actual subject, the 
whole background can usually be staged in 
(with brush) at once, but if the background 
appears too dark in comparison with the copy 
it is left clear for slight further etching. A 
blended background may be treated by staging 
in the darker half and leaving the lighter 
free to etch, carefully blending where the 
dark and lighter tones of the background meet 
by smudging the staging ink here softly with 
the finger. A white background is commonly 
handled by painting in the whole figure after 
being wholly finished as to tones, (staging 
and re-etching, etc.), and taking the back¬ 
ground down white separately. Smaller por¬ 
traits, of course, require less working in de¬ 
tail than larger, and at all times the etcher 
must rely on his own good judgment for the 
result reauired. Groups are handled much the 
same as individual portraits, although usually 
less fine detail and working up is necessary, 
but separation of the individual figures 
should be strengthened where possible by 
holding a dark figure and lightening an adja¬ 
cent lighter portion so as to slightly increase 
contrast and give an apparent “depth” and 
clearness to the group as a whole. Many o.'f 
the darker shadows can be quickly and easily 
handled by simply painting up the darkest 
portions and smudging or blending with the 
finger toward the lighter tones, painting clean 
and sharp, of course, where the detail calls 
for such handling. 

. Landscapes and general views, while 
quite simple after a little practice on different 
classes of subjects, will be found slightly 
more puzzling at first on account of the varied 
effects calling for varied methods of handling 
Practically every picture that represents 
an outdoor scene can be divided into two sec¬ 
tions, or general details, i. e ., foreground 
and distance, and usually also the space be- 
tween the foreground and distance? termed 
middle-distance”, contains the most important 
object and the sharpest details in the entire 
picture. The eye is not capable of focusing a 

—3S— 


distinct image of both foreground and dis¬ 
tance at the same time, and therefore the prin¬ 
cipal features on which the eye adjusts its 
natural focus will appear more clear and dis¬ 
tinct, the background or more distant details 
becoming more or less hazy or blurred. The 
foreground usually is more clear and distinct 
than the distance, being only slightly more 
blurred (generally) than the middle distance, 
so for convenience it will only be necessary 
here to consider foreground and distance. So 
far as the half-tone etcher is concerned, these 
terms are introduced here only because they 
have a decided bearing on the effect of a 
picture, producing atmosphere, strength and 
a certain natural attraction or “meaningness” 
that the etcher must strive to hold properly 
to do the work full justice. Briefly, for in¬ 
stance, l p t us first decide on the most impor¬ 
tant subiect in the picture, or the chief 
feature the photograoher or artist had in mind 
in makmg the original picture, which is 
very seldom in the “distance” except in strong 
cloud effects, sunset views, etc. We proceed 
to crayon or stage these parts where neces¬ 
sary, holding strong shadows, details, etc., 
working for tone and brilliancy in these prin¬ 
cipal parts especially, keeping the soft dis¬ 
tant objects more in reserve and less detailed. 
Some subjects will require more crayoning 
while others more staging; some may have a 
good deal of both while yet others should have 
little of either. A great deal of time and 
work can be saved sometimes in working up 
foliage by simply painting same over roughly 
with staging ink, using the brush fairly dry. 
In this way, while th/e shadows take the ink 
quite readily the higher lights will take care 
of themselves quite well, the brush seeming 
to slide over the dots somewhat rather than 
stick and cover the greater amount of chalk 
(magnesium) between. As stated before, this 
class of work is quite varied, each subject 
must be handled in its own way according to 
the etcher, and time and experience alone 
(beside artistic talent) will enable the etcher 


—3a— 


to judge well and quickly how best to handle 
each particular job. 

The next class of subjects, and a very im¬ 
portant one, which demands particular atten¬ 
tion is catalog work, silverware, jewelry, 
machinery, etc. Here again the subjects are 
so varied and the different requirements are 
so numerous that the etcher must learn by 
practice and a great deal of study of different 
subjects and effects before he can feel any¬ 
where near proficient. A good catalog illustra¬ 
tion will often be a great step toward selling 
an article, while a poor illustration even of 
a good article might be a hindrance to its 
sale. So it is easily seen how important the 
subject is, and the etcher must strive to retain 
so far as possible all tlbe delicate tones, bril¬ 
liancy, softness, sharp reflections, or other 
essential characteristics of the original 
copy. The majority of half-tone etchings 
of this class of work are made from 
‘'re-touched photos’', that is, from pho¬ 
tographs that have been worked up by an 
artist, using air-brush, lamp black and re¬ 
touching white, photograys, etc., and often 
from the amount of hand work becomes very 
valuable and represent the article pictured in 
its highest degree of perfection and pictorial 
beauty. It stands to reason, then, that unless 
the etcher does justice in reproducing it on 
copper* to compare very favorably with the 
artist’s re-touched (or worked-up) photo or 
drawing, the whole work and care up to this 
point has been practically for naught. If the 
subject in hand is a piece of silverware, the 
soft blended shadows and the bright spots of 
reflection must be watched carefully, bring¬ 
ing out the strong high-lights sharply when¬ 
ever called for. Care must be taken also not 
to lose the detail or distinct pattern, which 
distinguishes it from other designs. The 
proper “texture” or “surface” must be truly 
represented, a “satin-finish” being shown as 
a satin-finish, not as a “bright” polished finish 
but glass ware must retain its marked bril¬ 
liant glint , and this can usually best be 


—40— 


done by holding- some of the deepest shadows 
or cuts - solid black (or as nearly black as 
possible) while the highest lights or brightest 
reflections can be etched almost until the tiny 
speck of enamel on the dot are about to be 
lost,—(by re-etching). Furniture, as a rule, 
will be found comparatively easy, care being 
taken not to lose the grain or finish, and to 
hold the proper shadow side and proper tones 
on all narts. Caskets will usually be found 
quite difficult, both in the operating and the 
etching. It is usually best to stage in the 
whole black body at once after the flat-etch, 
handling bright nickle handles, etc., inde¬ 
pendently according to requirements. Silk 
lining can be crayoned if the crayoning is 
done carefully, handling it lightly and heavily 
as required to bring out the deep ruffled silk 
effect. Its light fluffy appearance must be 
held well, avoiding all tendency of heaviness 
or harshness. Yet, the detail must not be killed 
or softened in such a way as to look like 
velvet or other material instead of silk. In 
handling machinery, stoves, etc., the natural 
dark tones of the iron must be held well ac¬ 
cording to the copy. Usually one can start 
by crayoning in a few of the strongest shad¬ 
ows which lend themselves to the curves, pro- 
jectiohs, and other irregularities of the iron 
parts, ready for a short etch in the iron bath, 
taking care also, of course, of the crayoning 
and staging necessary on t'he nickel parts at 
the same time. Often a second staging and 
second short etch are required on machinery, 
and in this class of work, if in any, the oper¬ 
ator must do his part by producing a good 
negative in order to give the etcher any sort 
of a fair chance. Machinery is usually diffi¬ 
cult enough and requires considerable hand 
work, although an experienced etcher should 
know just about how best to handle the job 
at a glance. 

Short Etch 

After the crayoning and staging has been 
completed satisfactorily, it is burned in over 


—41— 


the stove until a wet finger touched to the back 
causes sizzling, as in burning in “spotting” or 
“touching up” on the print before etching. 
When the plate is cool, the magnesia is cleaned 
out with a weak acid solution, or “chalk remov¬ 
er”, preparatory to a “short etch”. This solu¬ 
tion merely dissolves the chalk, leaving a 
bright copper surface between the enamel dots, 
thus allowing free even action of the iron so¬ 
lution in the short etch. The chalk is best r-e 
moved by first wetting the plate under the tap 
and then flowing over it some of the acid so¬ 
lution, rubbing it over with the fingers or palm 
of hand, thereby not injuring the tiny dots in 
any way. A fine cleaning brush may be used 
if not too severely. When the chalk is all 
dissolved and the copper again looks bright 
and clean, the plate is dipped into the iron so¬ 
lution so as to insure even covering, placed into 
the two blocks as before, and again slid edge¬ 
wise into the etching bath face down as in flat¬ 
etching. This time, however, the duration of 
etching must be short (short-etch), as on it 
depend a great deal the smoothness and natural 
gradation of tone in the details or middle-tones 
of the finished job. Just as in flat-etch, of 
course, a coarse screen will require a longer 
etch than a fine screen to produce the same 
tone values. As a guide to the time of short- 
etch, an average of 1-Ms minutes may be used 
for 133 screen, or between one and two minutes 
usually, depending on requirements of the par¬ 
ticular job in hand. Anything over two min¬ 
utes is very apt to show too harsh gradation 
or steps of tone and show crayoning up too 
strongly. There are exceptions, of course. 
For 85 screen about 3 minutes might be struck 
as a fair average. While this short etch acts 
on the high-light dots as well as the middle 
tones, the highlights need not be taken into 
consideration just at present. If the negative 
from which the print was made is good, the 
highlights will be plenty large enough to stand 
the short-etch and still require more lightening 
later (re-etch). For the time of short etch or 
any certain screen one must judge especially 

-42- 


the middle-tones to determine the time accord¬ 
ing’ to the amount of lightening of tone re¬ 
quired. This soon comes with careful study 
and experience. 

Re-etching 

When the time of short-etch has expired, 
the plate is removed from the bath, well rinsed, 
dried with chamois, warmed slightly and pow¬ 
dered again with magnesia, and judged for 
color in comparison with the copy. The parts 
that had been staged in will, of course, remain 
covered, allowing no action of the iron solution 
on them; the middle tones will to a great ex¬ 
tent compare favorably in tone with the copy, 
but while these will likely require some work¬ 
ing up in tone here and there, the high-lights 
particularly will require to be lightened up 
and blended by hand. This part of the process 
is called “re-etching”, or sometimes “fine- 
etching”, and consists of lightening tones local¬ 
ly by hand, using perchloride of iron solution 
(same as the etching bath) and a stiff bristle 
or Chinese marking brush. The iron is brushed 
over the parts to be lightened, allowed to act 
on the copper a moment slowly etching the dots 
smaller in size and greater in depth, then 
swabbed off with a large tuft or ball of quite 
moist absorbent cotton. More iron is again laid 
on with the brush, allowed to act somewhat, 
and is again swabbed off with the cotton. The 
Chinese re-etching brush is held in the right 
hand and the cotton in the left, and used alter¬ 
nately until the dots over the various parts of 
the plate are reduced to the desired sizes. The 
first application of iron dissolves the magnesia 
out of the dots, thus making it impossible to 
judge the plate now by general color or tone 
as before. The etcher *must therefore learn to 
judge different tones by the different sizes of 
dots in those parts of the plate, also remem¬ 
bering, of course, that these sizes will vary in 
the different screens to give the same value 
or finished tone. 

Just as in staging and crayoning, no solid 
rule can be laid down for re-etching, but the 
workman must learn to depend on his own 


-4S- 


judgment and skill to know just where and how 
much to re-etch. A brief guide may be helpful, 
of course, always following the color and 
blended harmony of tone in the copy as 
closely as possible. In re-etching a portrait 
we can usually look for a strong narrow 
line of high-light down the front edge of 
the nose, and this can usally be lightened to 
considerable degree by re-etching, being care¬ 
ful, however, to hold the line narrow and 
sharp according to the copy. Hold the re¬ 
etching brush fairly perpendicular and draw 
the tip only along the high-light of the nose, 
allowing the iron solution to act somewhat 
before touching it with the wet cotton. After 
the plate has become wet in this portion the 
next application of the iron chloride will have 
a tendency to spread and blend rather than 
hold the high-light sharp and clear. As the 
application of iron begins to spread, the wet 
cotton must be brought into play at once, 
dabbing the etching solution off ‘ the metal 
and applying the tip of the brush again in 
a fine line, thus eliminating spreading and 
broadening of the high-light. The forehead 
and cheeks, especially on the lighter side, 
must nearly always be re-etched somewhat, 
but here the lights must be blended very soft¬ 
ly (following copy) instead of being held hard 
and sharp. The chin, also, usually requires 
a small blended spot of high-light, though 
this is sometimes kept more subdued than the 
cheek. The hair may require considerable 
toning up m the higher lights, rounding out 
the waves and curls, etc., in natural masses 
oi light and shade, bringing the tones in all 
cases as near as possible to those in the copv. 
A white collar must usually be lightened con¬ 
siderably, in many cases the highest lights 
becoming merely pin-point dots. No matter 
how fine the dots are, however, care should be 
taken not to lose the tiny speck of enamel on 
each dot. A pin-point dot generally refers to 
a dot brought to the smallest size possible 
without losing the enamel. If the enamel is 
seen to break away from its support from 


being too fine to hold or from too much brush¬ 
ing the re-etching must cease at once, as the 
printing surface of a small dot without enamel 
will enlarge on re-etching instead of decrease 
in size. The workman must train his eye and 
judgment to see quickly and at all times the 
shade of tone, softness of blending, and gen¬ 
eral natural effect of the copy and train his 
skill to bring his etched plate to favorable 
comparison with the copy. High-lights on 
white drapery can also often be reduced to 
pin-points where the copy calls for pure clean 
whites. The detail in any case, however, must 
be held well, and in this point the work is apt 
to fail to some extent unless carefully watched 
and skillfully avoided. White backgrounds 
will very often require dots, almost pin-points, 
but unless properly etched, very fine points 
are difficult to print cleanly upon the aver¬ 
age grade of book-stock, so unless the dots 
permit of good depth and are properly hand¬ 
led it is sometimes better to leave them very 
slightlv larger than the copy apparently 
calls for. This again depends on the skill of 
the etcher. Landscapes and general views 
must be handled each according to its own 
individual case. Where a copy calls for a 
white sky, that portion of the plate must be 
brought down quite fine, any cloud effects, of 
course, being held where required. Lakes, 
ponds, or other small bodies of water can 
usually be hanlled much like the sky, crayon¬ 
ing in such shadows and reflections as neces¬ 
sary, but are seldom as white as the sky. 
These small mirrored surfaces really borrow 
their color or tone reflected from the sky, so 
it is evident that there will be some resem¬ 
blance of tone at least. However, some of 
this sky hue is absorbed by the depth of the 
water, hence the water is usually slightly 
darker. A small point of this kind might at 
first seem insignificant, yet such little facts 
in nature have a decided bearing on the whole 
subject. Silverware, etc., must also be hand¬ 
led with careful judgment of the copy, re¬ 
etching the high-lights sharply cut or softly 


—45— 


blended in keeping with the subject at all 
times. Remember, however, that high-light 
dots usually increase slightly in size when 
printed onto the paper, so that where the copy 
calls for strong whites, care must be taken to 
see that they are quite fine on the etched 
plate, in fact slightly exaggerated if anything. 
Sometimes rough machine parts or castings 
which show no true hierh-light, but merely a 
lightened side produced by its rounded shape,, 
can be handled best by painting the whole 
article in after the flat-etch and then re-etch 
what is necessary after cleaning off the whole 
plate of its staging. 

Vignettes 

If the copy contains a soft vignetted shad¬ 
ow, the extreme light edge or boundary of the 
vignette (vin-yet’) is painted around with the 
staging brush after the flat-etch, simply draw¬ 
ing a line about the width of the brush, pay¬ 
ing no attention to the outer margin of the 
brush-line, but marking fairly distinctly the 
inner margin, or the extreme edge and shape 
of the vignette. This is burned in along with 
the staging and crayoning, and when the work 
is ready for re-etching, the vignette is re¬ 
etched . down carefully, blending well and 
procuring especially deep and sharp clean 
dots at the edges. In some special cases 
where a very long or large blended vignette 
is required, it is a good plan to rest that end 
of the plate (after otherwise finished and 
painted up for protection) into the iron so¬ 
lution, face up, and gently wash or paddle the 
iron over the vignetted edges with the hand 
or a broad brush. This method works clean 
and fast where it can be used, but great care 
must be taken not to carry the work too far 
and experience and constant watching are 
necessary. 

Cleaning Plate 

After the etching has all been satisfac¬ 
torily completed, chalking up the plate again 
during re-etching if necessary to watch the 


— 4 ( 5 - 


progress of the work, it is now ready for 
cleai mg up. Any chalk or iron stains re¬ 
maining on the etched plate can be cleaned 
off with the acetic or hydrochloric acid chalk- 
removing solution, rubbing gently in with a 
little bicarbonate of soda if necessary, and 
then dried with the chamois. If there nre no 
bad stains present, the plate can immediately 
be warmed well over the stove, and scrubbed 
over with gasoline to remove all staging ink 
and crayoning, using a stiff brush for the pur¬ 
pose. The brush must be fine enough, of 
course, and fairly clean so as not to scratch 
the enamel surface or delicate dots of the 
plate. A better solution to use for this clean¬ 
ing purpose is a mixture of benzole (or gas¬ 
oline), alcohol and turpentine, about equal 
parts. This will usually clean the crayoning 
and staging from a well warmed plate if 
anything will. After cleaning, the plate is 
again chalked up with magnesia to pass along 
to the “finisher”. 

The question has been asked, “Why 
should not the high-lights in the negative be 
small pin-point dots, or holes, as in a negative 
for “offset” work? The reason is this: the 
high-light dots in a half-tone plate must be 
deeper than any other part of the plate, es¬ 
pecially deeper than obtained by the “flat- 
etch”, because being small they have greater 
distance between them which would allow the 
paper to sink in and smudge in printing if 
they 'were shallow. The large size of the 
high-lights on the negative or print allows 
for this extra depth being gained while they 
are being brought down to proper finished 
size by re-etching. 

In any case, the quality of high grade 
etching that particular customers demand 
from fine conv depends greatly on the artistic 
skill of the etcher and his ability to adapt 
himself to the occasion. He must take pride 
in his work and a critical liking for the re¬ 
sults produced. And while the foregoing 
treatise might seem long and tedious and 
time-wasting, it is surprising how well and 


- 47 -- 


quickly a thoroughly trained and experienced 
workman can -produce the desired results, 
which should be both pleasing and profitable. 
At the same time, it is not contended here 
that all subjects at all times require or de¬ 
mand the care and amount of work laid out 
above. In some cases the work is deemed 
more or less of second grade, and in some 
the price quoted would not well permit it. 
But it is easier for a good etcher to swing* to 
an occasional rush cheap job than for a poor 
workman to turn out a fine job that Vill 
please the most critical customer. 

Machine Etching 

In this age of “speed”, when service and 
production are necessary to keep' pace with 
the times, many of the largest and begt 
equipped plants use Etching Machines. Most 
of the etching machines on the market and in 
general use throughout the country are very- 
satisfactory for their purpose, and do the work 
much more quickly than above described per¬ 
taining to the actual etching process itself. 
This is especially true in regard to zinc etch¬ 
ing, yet for some classes of copper etching, 
both line and half-tone, a suitable machine is 
a worthy asset. 

A very popular machine in use in many 
countries is the Levy Acid Blast. This is 
especially good for fast clean and deep zinc 
etching. Its working principal is a mixture 
of acid vapor and air is forced through numer¬ 
ous small nozzles at the bottom of the ma¬ 
chine or tank, spraying upward against the 
inverted zinc plate. The unprotected parts of 
the print, of course, facing downward and re¬ 
ceiving the full force of the acid spray, are 
etched away. The machine works smooth and 
clean, giving slightly tapered lines (if prop¬ 
erly powdered, in relief for printing. This 
machine simply takes the place of the rocking 
tub, doing the work faster, usually cleaner and 
with less tendency of under-cutting, and less 
fumes entering the workroom. The four-way 
powdering, of course, has to be used on each 


- 48 - 


bite just as in tub etching; this can also be 
well done by a machine, (Levy), if desired. A 
guide to etching time for line zinc with the 
Levy Acid Blast machine is: 

1st bite—30 to 40 sec.—air press. Y 2 to 
% lb. 

2nd bite—1 to IY 2 min.—air press. 1 lb. 

3rd bite. etc.—4 to 5 min.—air press. 1 lb. 

Another excellent machine, which has 
found great favor, is the Axel Holmstrom 
Etching Machine. This is quite suitable for 
either zinc or copper (the author has used it 
for both), and works on a principle of a paddle 
wheel, forcing a broken spray of acid solution 
against the plate, which is inclined against 
one side of the tank. The time for line zinc 
will usually range from about V 2 minute for 
the first bite to 4 or 5 minutes for the third or 
later bites, in all cases of course depending on 
the strength of acid, nature of the work, and 
the workman's general way of handling. For 
copper half-tones, of ordinary fine screen 
(133), the “flat-etch" will require from 2 to 
2 Y 2 minutes, reversing the plate end for end 
at the expiration of half the full time. Other 
screens timed in proportion. 

A third machine of merit is the Holt Etch¬ 
ing Machine, especially suitable for copper 
half-tone work where a machine is desired. 
In this machine, the copper prints, or plates, 
are laid on a table in the bottom of the tank 
of the machine, face up, and on lowering the 
table (and plates) into the etching solution, 
the lid closes and a disc automatically starts 
to revolve in a horizontal motion over the 
plates. On the under side of the disc are 
blades set at suitable angles to swirl the so¬ 
lution downward against the plates. 

Another good machine, the “Century", 
works on a principle of a dasher on which the 
plate is fastened face down. Here the plate 
is dashed or plunged against the surface of 
the etching solution by means of an electric 
motor, the solution forcibly impinging upon 
all exposed surface of the plate. 


— 49 — 


Still another, a “process” rather than a 
machine, is the Weeks Electrical Etching 
Process. This is used on copper halftone 
work, and the plate is “etched” by means of 
electrical action, or more definitely, by what 
is known as electrolysis. 

All these machines are protected by 
patents. 


“He touced the brow—the lip—it seemed 
His pencil had some magic power” 

—Wilson. 


— 50 — 


COLOR ETCHING 


Three-color Theory 

Three-color process work is based on the 
principle that all colors found in nature are 
represented by three primary colors mixed in 
suitable proportion. Just as the artist can, if 
he chooses, make a beautiful painting in in¬ 
numerable colors and shades, using only three 
properly chosen colored pigments, so can the 
color printer produce a wonderful duplicate of 
same by printing three properly-made plates 
in three properly-selected colored inks. He has 
the advantage, also, of producing as many 
duplicates as are desired, whether one or 
thousands. 

Color,- in the very beginning, can be di¬ 
vided into two great groups, i. e., “light” col¬ 
ors, known as “plus” colors) and “pigment” 
colors (known as “minus” colors) and found 
in printing inks, paints, and other coloring 
matters. Each of these groups can again be 
broken up into three divisions, known as 
“primaries”. When we break up a ray of pure 
white light, by means of a prism or a scientific 
instrument called a spectroscope, we find (with 
sufficient knowledge of science) that while 
seven distinct color bands are visible only three 
primary rays blend to form those different 
colors, namely: red (bright orange-red), green 
and violet. These are the “plus” primaries, 
such as compose white light, and the method 
of mixing is called the “additive” method, 
adding one color to another. Now, suppose 
we look at a piece of so-called pure “white” 
paper. What actually happens here is: that 
particulr paper has the power of reflecting 
all rays of the light thrown upon it back to 
our eye. Consequently, since all “light” rays 
blend when combined naturally forming 
“white”, we call the paper “white”. Now, let 
us print an impression of so-called pure “yel¬ 
low” ink onto the paper. The ink used has the 
power to absorb, or “subtract”, a certain col- 


— 51 — 






ored ray of the white light, which is really 
complimentary to the color of the ink used (in 
this case the violet). The so-called pure 
“primary red pigment” (more correctly “ma¬ 
genta”) printed onto white paper absorbs the 
green light (its complimentary) and the pure 
“primary blue pigment”, which is practically 
a strong cyan or peacock blue, absorbs the 
bright orange-red light (its complimentary). 
The three “minus” primaries, when mixed by 
printing one over the other, form black (ab¬ 
sorbing all light rays). This method of mix¬ 
ing the pigment colors is called the “sub¬ 
tractive” method. The third method of pig¬ 
ment color mixing might also be mentioned 
here: the “juxtaposit” method, in which small 
particles of different colors are placed very 
closely adjacent. An excellent practical ex¬ 
ample of this method is the Lumiere Auto- 
chrom plate, while a very simple and common 
example might be found in a distant wooded 
landscape in autumn. In the latter, the sub¬ 
ject in view is really composed of innumerable 
vary-colored leaves, bright yellows, reds, a few 
greens, browns, etc., while at a great distance 
the optical nerves become so confused that all 
colors appear to blend into a fairly even hue. 
So, in short, careful scientific research has 
proven that the “plus” (light) colors and the 
“minus” (pigment) colors are very closely re¬ 
lated and dependent on each other, and in 
studying them we must not get the two terms 
confused. However, the color etcher need only 
deal with the minus or pigment colors, but he 
must acquire a thorough knowledge of those. 
Yet, a slight knowledge of the “separation” of 
the minus primaries for his work will not 
come amiss. 

The artist’s painting, then, or any other 
object that is to be reproduced, has gained its 
colors by the use of only three pigment pri¬ 
maries, yellow, red (or magenta) and blue. 
For the three printing plates, then, these three 
colors must be separated, or “unmixed” as it 
were, one color for each plate, so that when 
the finished plates are again superimposed on 



paper in the printing press in the same pig¬ 
ment primary colors as were “unmixed” in 
the negatives, the primaries will again be 
mixed in the same proportions as they were on 
the corresponding parts of the original paint¬ 
ing or object. This color separation is done in 
the camera by photographing through color 
filters, each filter being a suitable transparent 
stained glass of a color complimentary to the 
color to be separated (or “unmixed”) from the 
painting. The negatives must, of course, be 
rendered in Half-tone for Copper Etching. 
Here also, as in reference to the half-tone 
negatives in the Introduction, details of opera¬ 
tion must be omitted. The accompanying dia¬ 
gram will suffice in a very simple form, to 
give the reader a clear conception of the gen¬ 
eral idea. 

GREEN IKHT REFLECTED FROM 
TREE PASSES THROUGH GREEN 
F/i TCP, REMAINS GREEN UCHT, 
ACES ON PLATE, GlUAIG 
OPAQUE PORTION OP NEG¬ 
ATIVE. 

■*-COtOR-SFA/SIWT PLATE. 


RED LIGHT REFLECTED FROM 
HOUSE /SABSOR3ED BT GREEN 
FUTER (ITS COMPUMENTAR/J 
PRACTICAL!T FORMING BLACK 
(OR ABSENCE OF L/GHl), THERE¬ 
FORE NO ACTION ON PL ATEJHIS 
' REMAINING CLEAR CLASS,— 
f RED PRINTING PLATE. 

The color half-tone negatives must not be 
made at the same screen angle, or the regular 
dots of the successively printed plates would 
simply cover those of the previous plates, 
destroying the color effect. Therefore, each 
negative must be made on a different screen 
angle. When two or more half-tone screens 
are superimposed at very small angles an un¬ 
pleasant regular pattern is produced. To 
avoid this, the stronger colors are kept at as 
great angle apart as possible. The following 
angles are found to give good results. The 
final mixing of the colors in printing, then, 
is by a combination of the subtractive and 
juxtaposit methods. 


C/PTT/V FILTER 



PORTION 

Pdfay/yerC 
















3-Color Angles 4»-Color Angles 

ETCHING 

Color etching is done practically on the 
same order, so far as the general manipulation 
is concerned, as ordinary black-and-white cop¬ 
per half-tone. The great difference between 
the two is the fine conception and knowledge 
of color required. For this purpose the etcher 
must train his eye and mind carefully to be 
able to judge and compare colors, shades, tints, 
strengths of tone values, etc., as well as detail, 
softness, and atmosphere in a picture, and 
also have a thorough knowledge of the mixing 
of the three pigment primary colors. For 
convenience and simplicity, we will call the 
magenta pigment simply “red”, as it is com¬ 
monly called, the pigment primaries, then, be¬ 
ing yellow, red and blue, of absolute purity. 
To this end, a good etcher’s color chart may be 
found helpful, by which colors can be matched 
to some approximate degree and the dot for¬ 
mation in each primary studied, the etcher al¬ 
lowing for slight differences in his plates com¬ 
pared with the chart where necessary to pro¬ 
duce the desired difference in the final printed 
color. A good knowledge of black-and-white 
half-tone etching is very necessary, of course. 

A few remarks here, however, will be re¬ 
quired. Color negatives are not stripped and 
reversed as other negatives, on account of 
liability in so doing of being distorted and 
stretched more or less so that the plates would 
not fit, or “register”, in printing. They are 
reversed into the proper direction in the mak¬ 
ing, and also the operator usually flows them 


— 54 — 










with a gum “wet plate varnish” (when wet 
plates are used) so that no rubber and strip¬ 
ping collodion is required to protect the delicate 
surface. The printing is done on copper by the 
enamel process as in the black and white work, 
care being taken to get uniform prints on all 
colors and a properly timed flat-etch on each. 
If process dry plates are used, for the screen 
negatives, no coating is necessary, and the 
general handling is the same, except that a 
slightly thinner coat of enamel is advisable 
and over-printing must be avoided. If the 
negatives (either wet plate or dry) were prop¬ 
erly made, the shadow dots in the red printing 
plate will usually be larger or more open than 
in the other two. This has a tendency toward 
softnes, and the proofs will show up less 
harsh and hard than if the shadow colors were 
strong in all plates. In fact, the etcher must 
avoid too much red in the entire job, as the red 
(magenta) ink is apt to print up stronger than 
at first estimated by the novice color-worker. 
The yellow plate is usually the heaviest and 
most lacking in detail; the blue usually shows 
most detail. Before being able to acquire by 
experience the knowledge of just how each 
plate will print up in its respective color, the 
etcher must have a keen mental conception of 
the exact hue and strength of his process inks. 
The printed results can sometimes be remedied, 
of course, by slightly changing the inks (such 
as, a heavy red plate can be compensated for 
in color by printing in a weaker red pigment, 
etc.), but this is bad practice. Learn the 
standard strength of color used, and etch the 
plate accordingly. To reproduce the copy faith¬ 
fully and cleanly, it is often necessary to elimi¬ 
nate entirely certain primaries from some por¬ 
tions. For instance, in pure clean light greens 
the red must be eliminated entirely; in pure 
purples the yellow, etc. This is done by cut¬ 
ting away those portions from that particular 
plate (by the “finisher”), and the etcher usu¬ 
ally marks those parts by scratching or other¬ 
wise. In some classes of work, such as land¬ 
scapes, etc., the distant horizon will be too 







heavy and strong 1 in detail. This can.be soft¬ 
ened by “running through” with a “lining tool” 
to match the screen used; handled by the “fin¬ 
isher,” or preferably by the etcher himself (see 
“Finishing”). By this method those parts are 
lightened and softened, at the same time 
breaking up detail and giving more “atmos¬ 
phere” to the picture. 

The foundation color process is the three- 
color, using 3 plates and printing in 3 full- 
strength primaries. The best permanent 
printing inks obtainable, however, are not per¬ 
fect in their reflection or absorption, so a 
darker blue must be used to get strength in 
the shadows. The 4-color process, using 4 
plates and printing in 4 colors, yellow, red 
(magenta), blue and black, is based on the 
3-color, gaining more delicate softness and 
ease in rendering by using a much lighter 


blue (peacock or cyan) and strengthening the 
shadows and details by the aid of the black. 
The black plate must be very light in tone, 
or “grayed-down”, or the whole job will be 
unpleasingly heavy and the color “killed”. 
Sometimes, however, the fourth printing is 
run in neutral gray; in that case, the “black” 
plate will be heavier, much like an ordinary 
black and white half-tone. There is one ad¬ 
vantage in using the black instead of gray in 
printing; that is, type matter, etc., can be run 
in black along with the black fourth printing 
color, thereby saving an extra press run. Duo- 
tones, or two-color half-tones, are affiliated 
with these processes, although they are usu¬ 
ally made from black and white drawings or 
photos, and the colors “faked” in the etching. 
They can be run in any colors desired, but are 
generally etched for black and one of the sec¬ 
ondary colors,, or two suitable complimentary 
colors. Their screen angles are generally 60 
degrees and 120 degrees. The negative for 
the key plate should usually be fairly high, 
and that for the tint more flat with plenty 
of color (medium flash, long straight, and 
little or no high-light exposures). 

The “Duotone” example in the Appendix 






was “faked” from a black and white photo (en¬ 
tirely, including photo, by the author), on 150 
screen. The 3-color example is on 166 screen,, 
and the 4-color on 150 screen, both from 
opaque water-color drawings and color-separa¬ 
tion negatives. The 3-color Chart is on 133 
screen. In using this chart, the large rectang¬ 
ular color patch is chosen which best repre¬ 
sents the color to be reproduced by the print¬ 
ing plates. To the left of this patch will be 
found smaller square patches of the primaries 
in their proper dot strengths, of which the 
larger patch is composed. Each primary 
square should be examined under a linen 
tester and the dots matched in the etching of 
the corresponding plate. Any slight difference 
in color required, according to the copy, can 
be rectified by the etcher, by merely leaving 
more or less color in the proper plate or 
plates. 


Art is natural—not manufactured; 

Yet plans' natural resources are still undiscovered* 

' — 57 “ 




FINISHING 


Finishing is the branch of photo-engrav¬ 
ing dealing with hand tool work in general. 
It is closely associated with and aided by “ma¬ 
chine work”, but the latter will be introduced 
only for necessary explanation. 


Outlining 


The first step, and a very important one, 
is to learn well the tools and their uses. Few 
tools are really necessary if the finisher is a 
real “finisher”, although numerous others may 
be added for special purposes, according to the 
workman’s liking. A “finisher’s pad” is, of 
course, essential, on which to rest the plate 
while tooling it. Illustration “A” shows an 
“outliner” (or angle tint), one of the princi¬ 
pal tools used and perhaps the most important 
regarding choice of shape. It should be of 



i 


comfortable length to fit the hand, not too 
long, with a fair sized handle. The bottom 
edge is slightly curved, enabling it to be used 
over a large flat plate without the heel, or the 
handle, interfering; the edge proper should not 
be a “knife edge”, but of sufficient width 
(rounded or flat edge) to cut a fair clean line 
without raising a “burr” on the curves; the 
point should be ground at an angle of about 45 
deg. and touched up carefully on a hard oil 
stone, testing for sharpness by catching point 
in the finger nail. About a No. 6 (Muller's 
make) or a No. 8 (Murphy’s) is very well 


— 58 - 







adapted for the purpose. It is used princi¬ 
pally for “outlining’” or cutting a line around 
ovals, machinery, jewelry and silverware, etc., 
and other “cut-away-background” work. Its 
method of use is as follows: Suppose we have 
a copper half-tone portrait (or any other sub¬ 
ject) reouiring to be cut down to an oval 
shape. First, the oval must be “outlined”. 
If the negative has been trimmed to size and 
shape before printing, we have merely to fol¬ 
low th oval etched on the plate; if not, the 
oval shape must be marked in position by 
scratching around a “cut-out” form with a 
“scratch-point”. This scratched line is then 
used as a guide for outlining. The proper 
method of holding the outliner is shown here¬ 
with. 




On picking up the tool from the bench or 
table, the handle is first grasped into the 
fleshy part of the right palm, holding it tightly 
in position with the last two fingers, the end 
of the little finger placed against the corner 
of the large ball of the handle and the next 
finger tipped against the ferrule. The other 
two fingers are placed close together along 
the right side of the tool proper, and the thumb 
extended along the left side forward of all the 
fingers. The thumb is the principal guide for 
the point, and on it rests a good share of the 
responsibility. The tool must not be “en¬ 
closed” in the hand, but held only by the tips 
of the four fingers and the inner side of the 
thumb, so that the tool, fingers and thumb may 
be slid over a flat plato with all practically 
touching the surface. At first this grasp of 
the tool might feel very awkward and tire¬ 
some, but in time it will become as loose and 

59 




natural as picking up and using a pencil. 

Now, the point of the tool is placed 
against the scratched oval line for outlining, 
the hand raised bringing the tool to about 30 
degrees with the plate, and just a slight 
pressure given to insert the point barely un¬ 
der the surface of the metal. The hand is 
then lowered until it rests on the plate, and 
the fore part of the tool is practically parallel 
with the plate and only slightly below its sur¬ 
face. The back part will now be just off the 
metal so that it will not rub or scratch. Now 
with a steady and careful movement of the 
hand the tool is pushed forward, being care¬ 
ful 1 to maintain the proper depth to keep it 
running smoothly in place. By lowering the 
handle slightly too much the point is raised 
and forced out, perhaps sliding directly across 
the work and ruining it. By raising the.handle 
the tool is forced downward into the metal too 
deeply, causing difficult cutting and possible 
si inning out on account of too great uncon¬ 
trolled force being applied. So, practice is 
the only method whereby the finisher can gain 
self-confidence and feel safe. When one has 
once mastered the tool in outlining, other tools 
and uses will be found more simple. In cut¬ 
ting straight lines, the plate is held steady by 
the left hand and the tool (in the right hand) 
is simnly pushed sraight forward, following 
the line to the proper depth, but in outlining 
an oval, or any other curve, the tool point Is 
held more or less steady and the plate is 
swung, or pivoted, on the finisher’s pad. The 
plate is swung in the direction of the hands of 
a clock, tooling on the far side of the oval, 
thus keeping the axis or centre of that part of 
the curve always toward the workman. There 
are occasions, of course, when working on the 
near side of the oval is handiest, such as in 
very large work, but when one becomes ac¬ 
customed to the other method, keeping in mind 
his own body as being the axis or centre of 
the “swing”, he will find an advancement in 
both speed and accuracy. Of course, the tool 
must be pushed ahead slightly as well as die 


plate being* swung, according to the curve, the 
larger the arc the more the tool must travel 
ahead and the less the plate must swing. On 
very small arcs or circles sometimes the 
swinging of the plate is the only motion re¬ 
quired. At the same time, in swinging the arc, 
the tool must be inclined, or “canted”, toward 
the workman; in the same manner as a bicycle 
or race-horse leans toward the centre when 
rounding a curve. The sharper the curve the 
more the tool should be inclined, thus giving a 
smooth-cut line in all cases. In outlining 
machinery, jewelry, etc., where curves may 
ran in one direction and then swerve into an¬ 
other direction, that is, the outline of the ob¬ 
ject may be partly bulged or “convex”, ana 
partly indented or “concave”, one part of the 
curve is swung (as directed) and then the 
plate turned round to bring the next part of 
the curve into proper position for cutting, each 
sweep being cut as a separate curve and neatly 
joined at their meeting point. When two lines 
meet in an angle (what might be called an 
“internal angle”), such as is often found in 
furniture outlining, care must be taken not to 
let the back edge of the tool mar the corner 
by dragging or pressing into it on starting 
the line. This can be avoided by immediately 
starting the tool ahead as it is being lowered 
into the metal, doing away with all “prying” 
action at the corner; or sometimes both lines 
can be finished at the corner instead of start¬ 
ing there. In the latter case, at the imme¬ 
diate end of the line the point must be lifted 
straight up so as to snap off the little burr or 
shaving which the tool ploughs up ahead of it. 
If this is neglected, each corner will have a 
tiny point of metal rising from it, giving the 
effect in printing of a black dot centering a 
very small white circle instead of a clean 
square corner. 

The Router. 

After the outlining is completed, the plate 
is passed on to the machine room to be 
“routed.” The “router” is a machine which 


—61 — 




cuts aw? ir the background or the metal that is 
not wanted on the plate, by means of a cutter 
or bit revolving in a vertical position at great 
speed (about' 14,000 R. P. M.). This removes 
the surplus metal, leaving (besides the actual 
outlined job itself) only a thin irregular line 
of metal outside the outlining, and a flange 
ail round about Vs inch wide and VL the thick¬ 
ness of the plate, which flange facilitates 
nailing the “cut” onto its base block later. 
The router is also used extensively on line 
etchings to remove the surplus zinc. 

Trimming Up. 

Illustration “B” shows a flat bottomed 
tool, or “chisel.” After the plate is routed, 
the finisher trims off the irregular line left by 
the machine, leaving a clean smooth edge to 
the whole half-tone design. For this purpose 
the chisel is mostly used, especially on all 
straight ed<>es and convex curves (such as 
around ovals). This tool may be simplv 
pushed sraight ahead, if there is not too thick 
metal to cut away, or in case of a heavy tough 
cut it may be used with a sort of “draw-cut” 
or scythe motion, starting the stroke with the 
lower corner of the tool (held edgewise) and 
drawing the tool downward as it moves ahead. 
In this manner, of course, only short con¬ 
secutive strokes may be taken, but fairly 
heavy work can be done with speed and ease. 
Unde^ no circums f ances should the chisel have 
a twisting or prying action, or a corner is al¬ 
most sure to be broken off. On concave 
curves, especially small ones, as often found 
on machinery cuts, the round bottomed tool, or 
gouge, should be used (illustration “C”). 
This tool will not scrape the edge in following 
around as the chisel would. It is also used for 
jabbing or digging out corners and small 
places too small to be routed out. The gouge 
can be twisted considerably without danger. 
In fact, many long, narrow spaces can first 
be rough-cut by using the gouge with a 
twisting or wiggling motion, then smoothed 
up with a steady straight sweep of the same 
tool. 


Spotting. 

Where breaks, slugs, etc., are allowed to 
enter into half-tone work, these defects must 
be corrected or “spotted” by tooling. Illustra¬ 
tion “D” shows a “knife-edge” tool, same style 
as the outliner except finer, which is used for 
“running through” high-lights and middle- 
tones where solid spots occur in these portions. 
For instance, suppose we have a soiicl spol 
in a sky or other high-light. The knife edge 
tool (usually a No. 1 or 2) can be used to 
break up the spot into new dots by continuing 
the lines between the regular rows, running 
! through one way, and then crossing at right 
I angles, following the screen angle in each 
direction. The space must be cut wide enough 
to trim the dots down to correspond in size 
| with those around them. To do this it might 
i be necessary (except on the very fine screen) 
to use a coarser tool (about midway between 
| the knife edge and outliner): or the desireo. 

I effect can be produced by running through 
each way twice with the fine tool, once canting 
it toward the left and then to the right, thus 
! cutting down the dots on four sides. The 
pressure or depth of cut also helps control the 
size of dots. A very smooth effect can be 
gained, esnecially in the coarser screens, by 
cross-lining as explained above, then cutting 
through again very lightly with a fine tool in 
two directions at 45 degrees to the screen 
angle, or ordinarily parallel with the sides of 
the plate. This simply cuts off the tiny cor¬ 
ners of the dots, making them more nearly 
round and less noticeable; but it should not 
be attempted unless done with skill and care, 
or it 1 s apt to look worse instead of better. 
Sometimes bad spots can be entirely obliter¬ 
ated in this way. The middle-tones can gener¬ 
ally be handled the same way as high-lights, 
with a fine tool, but much less pressure must 
be used on the tool and very carefully judged 
in order to match the tone. The lighter 
middle-tones can generally be run through 
light> r both ways, while the darker middle- 
tones will often stand only one way, and then 




ve y, ' ,r lightly. If very dark, they must be 
treated as shadows, only opening up more to 
match the surrouding tones. For spotting 
shadows a tool like “E” should be used. This 
has an elliptical point, is fairly short and 
stubby so it can be held quite perpendicular 
with the point sharp but not too slimh r tan- 
ered. ^or fine shadow dots just a slight touch 
with the point, holding the tool upright, and 
at the same time giving it a very slight twist, 
will duplicate almost any small round shadow 
dot or hql^ 

Sometimes a scratched half-tone can be 
repaired qhite easily, while other times it is 
next to impossible. The metal is pricked up 
by raisin^ a series of tall burrs in the path 
of the scratch, one directlv behind the other, 
and the spaces well filled by rubbing soft 
solder wire into them. Then with a “burnish¬ 
er” or fiat “scraper” the solder and burrs are 
rubbed down solid ?nd level with + he sur¬ 
rounding surface. If necessary, the scraper . 
may be used to cut or shane off the surplus 
metal. When the scratch is filled up solid, 
all that remains to be done is running through 
or picking shadow dots as required to match 
the screen, as in ordinary spotting. 

Various Tools and Uses. 

Figure “F” shows a small gouge very 
useful in trimming up in small places In con¬ 
junction with figure “C”. Figure “G” is a 
coarse outliner, handy either for gouging out 
narrow places or outlining zinc (a coarser tool 
works better on zinc than a fine). Figure “H” * 

is a lining-tool, and is quite distinct from the 
outliner. This is a sort of multiple tool, or a 
tool grooved along its bottom edge so as to 
cut a number of regular lines at one time, 
each tool made to match a standard screen 
ruling. The coarser tools (85 to 120 lines } 
per inch) are often used in lightening or 
breaking up “Ben Day” stipple and grain 
tints, but the finer rulings are used mainly in 
breaking up detail, etc., in half-tone work 
(especially color-work). In color-work, the 
finisher, or etcher himself, uses a lining tool 




which matches his particular job to rui. 
through heavy shadows in certain plates, to 
break up harsh or strong’ detail, sometimes 
to smooth up a roughly-broken screen effect. 
The method of use, in this work, is not to 
push the tool forward, but to track it in the 
screen ruling and draw it backwards through 
the defective part. In all cases, in running 
through, spotting, or wherever “tone” is the 
point in view, the plate should be kept chalked 
up with magnesia to follow progress of the 
work. Also, the linen tester should be used 
freely. For some work, such as fine outlining, 
color-finishing, etc., a large finisher’s glass 
on a stand will be found very useful. This 
should be about 2 in. or more in diameter, 
and not too short focus, so that the field of 
view is large and there is plenty of space to 
use the tools between the glass and the work. 
In color-finishing, care must be taken to cut 
true and exact, leaving just a hair-line margin 
on each cut color to allow for register in 
printing. 

“Square Finish” Half-tones. 

“Square finish” is the simplest form of 
trimming half-tones, and is done by a “bevel¬ 
ing” machine. This machine trims up the 
straight edges of the plate, forming also a 
beveled flange for subsequent nailing onto the 
mounting block. These edges might be simply 
trued up with a plain straight finish, or they 
might have a narrow black border line. For 
the latter the negative should have been 
squared to size before stripping, then it is 
only necessary to adjust the plate in the bev- 
eler so as to cut slightly outside the etched 
half-tone. The black border line, however, is 
generally accompanied by a fine white line 
cut immediately inside of it. The white line 
may be done with a “draw tool” before flat- 
etching, or on the beveler if the machine has 
a gTaved-line attachment. In using the latter 
attachment, the white line on each side is not 
cut quito to the corner; these unfinished cor¬ 
ners arc later joined up accurately by the 
finisher, using an outlining tool. This is 


generally done at the time the plate is being 
“spotted.” 

No acclount has been mentioned of the 
^her machines, such as the saw for cutting' 
wood and metal, the guillotine for cutting- 
metal. the trimmer for truing up the blocks 
after cuts are mounted, the nlaner and type- 
high machm- for planing down the blocks 
to proper thickness, the drill and jig-saw for 
mortising, etc., as these belong directly to the 
machine work and not connected with the 
actual “finishing.” 

Re-Engraving. 

In fiiany fine half-tones, especially in high 
class advertising cuts, we find various white 
lines Pooled through backgrounds, high-lights, 
lighter middle-tones, etc., merely for artistic 
effect. These are tooled in bv.hand according 
to the talent and taste of the finisher. The 
work is known as “re-engraving”, and being 
considered special hand work, is seldom done 
on a regular job unless so ordered, as “extra”. 
It calls for more artistic skill and tasteful 
judgment than any other branch of finishing, 
and as the designs and patterns used are 
almost unlimited, careful study and patient 
practice are the best guides to it. The student 
in this art should learn to study the lines and 
patterns of other finishers’ work and then 
build his own ideas along these lines. One 
suggestion, however: don’t cut all the detail of 
the picture away by too much tooling. The 
result will be very distracting and unpleasant. 
Also, try to run the pattern in each separate 
division or subject of the plate with a differ¬ 
ent general direction, yet not too abruptly 
broken. Keep the tooled effect smooth and 
pleasing in appearance at all times. 

Zinc Work. 

Zinc finishing (line work) is practically 
“cleaning” the etchings of rough spots, irreg¬ 
ular lines, etc., and the main tools used are 
the chisel and gouge. If a line is “chewed,” 
routed into, dented by being struck, or other¬ 
wise broken, it can usually be repaired by 


- 66 — 


soldering: and trimming’ up. The metal is first 
pricked up with a tool so the solder will hold, 
cleaned with “flux” (or hydrochloric acid cut 
with zinc), solder applied (using* a soldering* 
copper or jeweler’s blow-torch), and then 
trimmed down to shape. Or, if the hole is not 
too large, the metal can be borne up well by 
iabbing into the sides of the line with a stout 
tool, then prying up slightly several times, 
rubbing the spaces full of soft wire solder, 
then burnishing down and trimming, much 
cn the order of repairing a scratch in half¬ 
tone work. A small piece of “Scotch stone” 
is very useful in zinc work in polishing down 
an irregular surface. 


“One picture is worth more tlmn ;i million words, 
if the picture is right/’ —Brisbane. 


PROVING 


To save space, this chapter will be out¬ 
lined in very brief form, yet as detailed as 
possible under the circumstances. 

As the average customer cannot judge 
an engraving, especially a half-tone, from 
the plate alone, it is customary to submit a 
“proof” or printed impression on paper along 
with the j£»b, showing the result the printer 
should produce from the plate. Most regular 
oroving is done on a hand proof press, which 
consists principally of a flat iron “bed” on 
which the plate is laid for proving, a flat in¬ 
verted “platen” under which the bed is moved 
along a track and a handle or lever by which 
the platen is forced down, imparting a great 
even pressure against the plate. There is also 
generally a “tympan”, or canvas, stretched on 
a framework, hinged to the bed, acting as a 
cover for the whole work while proving. 

In short, a small quantity of the proving 
ink, as bought, is rolled up on the glass, 
stone, or zinc slab for the purpose, using a 
regular composition proving or press roller. 
When the ink is properly distributed, the 
roller is passed several times over the plate, 
or “cut”, leaving an even coating of the ink 
on its surface. The cut is then placed face 
up on the bed of the press (so as to centre the 
pressure), the paper adjusted on the cut and 
padded with several other sheets of paper or 
vsmooth cardboard, the bed slid under the 
platen, and the pressure applied. It is then 
released, and the paper pulled carefully from 
cut, with the ink design adhering to the paper. 
Care must be taken to use the proper kind and 
amount of ink. and just enough pressure to 
leave a clean complete proof without “punch¬ 
ing” through the back of the paper sheet. 
Proving, (either Black-and-White or color), 
just as every other branch of engraving work, 
must be done with care and judgment, and a 


68 



fair knowledge of the materials used. If the 
proving is done on the power press (as color 
work often is) the same general rules apply, 
with necessary alterations of use. 

Inks. 

The exact details of the manufacture of 
printing and proving inks is more or less 
difficult to study thoroughly, partly on account 
of the secrecy in which the> formulas and 
methods are held, and partly on account of the 
varied ingredients used in the manufacture 
as a whole by the different makers. The fol¬ 
lowing will give a fair idea of the principal 
materials commonly used in ordinary black 
printing (or proving) inks: 

Basic Ingredients— 

Pigments:—Gas Black (for finest). 

Lamp Black (for cheaper). 
Vehicles:—Linseed Oil Varnish (for 
best). 

Rosin Oil Varnish (foi; cheaper). 
Petroleum Oil and Paraffine (for 
cheapest inks). 

Subordinate Vehicles:—Gum Varnish, 
Japan Drier, 

Asphaltum, 

Soap. 

In ink tints, Zinc White is used for typo¬ 
graphic Opaque inks, and Aluminum Hydrate 
for Transparent inks. 

The principal pigments used in colored 
inks are divided into two general groups,— 
the natural mineral pigments, chemically com¬ 
pounded, and the coal tar dye products, known 
as “lakes”. The former class includes most 
of the ordinary colors used in printing inks, 
but some of the purest and strongest colors, 
especially process red (3-color), are obtained 
from the latter class. These lakes are again 
divided into three classes, roughly, as to bril¬ 
liancy and permanency. The most brilliant 
lakes are derived from analine dye (coal tar 
product), but are not so permanent as the 
other two weaker classes, which are from 
naphthalene and anthracene. So where per- 

<;9 


manency is a necessity in these colors bril¬ 
liance must be. sacrificed to some extent. 

There are several points to consider re¬ 
garding the vehicle used in an ink, the most 
important being its drying qualities. The ink 
(especially process colors) should dry fairly 
rapidly in order to superimpose the different 
colors without great loss of time. Yet, too 
fast drying, especially on fine super-calender¬ 
ed proving paper, will cause the pigment to 
lie on the surface in the form of a loose pow¬ 
der. Linseed oil varnish is used in the best 
inks as the principal vehicle, having good 
drying qualities as well, as fine elasticity, 
thinner grades being used for fast press inks 
and the heavier for half-tone and hand press 
work. 

In all cases, the ink, paper, and press 
used are infinitely related. An ink considered 
excellent for one sort of paper and press 
action might be worthless on another class of 
work. 

General Suggestions. 

Use good ink:—the best obtainable for 
the purpose. For half-tone proving a fine stiff 
ink rich in pigment is required. Roll up well 
and often in preference to “flooding” cut by 
using too much ink. Cheaper grade inks, 
containing too much oily base in proportion 
to pigment are not suitable for fine half-tone 
work. Ink too soft (different from lacking 
in pigment) can be stiffened by adding very 
little Sodium Silicate (ordinary water-glass). 
If too stiff, add “Reducing Varnish” (made by 
ink makers). Perfect half-tone proof should 
reproduce cut, dot for dot, in size and shape 
of dots. For line work (and coarse screen) 
a little more or softer ink can be used. All 
inks stiffer for hand press than for power 
press. Special “Driers” (made by ink makers) 
added when rapid drying is necessarv 

Rollers:—Soft or medium composition 
for winter, hard for summer. 

Sudder* changes of atmosphere make 
trouble on ink and roller. Never use alcohol 
on roller; plenty of benzine and clean rags; 


■ 70 — 


let dry before inking at once. Slight trace of 
benzine on roller or slab makes ink lay washy 
or "reasv. 

Tints:—'Use “Tint Base” or “Mixing- 
White”. (See Printers' Color Chart). Tint 
base comes in heavy form (hand press) and 
thin syrupy form (power press). Use proper 
amount to produce the desired tint when cut 
is fed with nroper amount of ink, without 
ever- or under-inking. Do not use tint base 
and white in same mixin°”—will cause ink to 
lay mottled and uneven. Use base for trans¬ 
parent and white for opacme effects 

Bronzing:—Geld or silver in 1r can be 
mixed and used as ordinary ink. with “Gold 
Varnish” (made by ink makers) and Gold 
Bronze ~r Aluminum Bronze. Difficult to 
handle, dries fast and hard, and will ruin 
rollers if not weB cared for. Best work, a^so 
handiest for a few proofs, is procured by 
“Bronzing”. For this, use “Gold Size” (made 
by ink makers!, which is very much like vel- 
low ink, but more adhesive; puli pvoof with 
this, then dust over with Gold or Aluminum 
Bronze, using large tuft of cotton. 

Viemettes (Vin-yet):—Pull prove on about 
3-nlv litho board or “post card stock.” Cut 
with sharp rounded knife or shears around 
edge, ’"‘referabh 7 just inside edge of job, shave 
oif to "pride slope from bottom surface of 
card ^ inside edge of vignette at top surface. 
Success depends on careful cutting and shav¬ 
ing down. Glue in position on “tympan” to 
fit cut ’^operW when in position for proving. 
(This can be done by first pulling impression 
on tympan sheet.) After paper stock has 
been placed over inked cut on press bed, tym¬ 
pan (with overlay) is placed down on it, 
pressure naner or padding on top of tympan, 
next to platen of press. Sometimes sheet (or 
two) of heavy proving stock between overlay 
and paper helps soften vignetted edge. 

Movement or “Slur”:—Double or elon¬ 
gated dots indicates movement of cue while 
proving. See that cut is centered for “press¬ 
ure/ the heavier parts of printing surface 


- 71 - 



nearer centre of press bed than lighter detail 
parts with little surface. Try block (if cut 
is blocked) for uneveness or warp; if it rocks, 
build up with paper under low corners or 
place whole cut on several sheets of soft paper 
or blotter stock. See that plate is mounted 
solid and flat to block. Use bearers (height oi 
wood) on sides. 

Color Proving:—This is an art in itself, 
and the results depend considerably on the 
skill of the prover. While proving stop-out, 
tint-plate work, etc., belong to color-proving, 
this latter generally refers to process plates. 
The general notes on half-tone proving ap¬ 
plies also to color work, and only a few brief 
additional suggestions will be given here. 

All color-register work on hand press must 
be done by aid of a “register gauge," in which 
the blocked cuts fit evenly, and the paper is 
fed against three adjustable pins or guides so 
that each impression will fit in precisely the 
same position on each sheet. The pins are 
adjustable (by screw action) so that the pa¬ 
per, or first color impression, may be brought 
into “register" or super-position with the 
different blocks, allowing also of blocks being 
of different sizes if necessary. With power 
press this is accomplished by screw-adjusting 
gauge pins fastened into tympan sheet of 
piaten. The lighter colors or tints are gener¬ 
ally run first, the final impression being from 
the “key plate." 

Duotones are proved (generally) tint half¬ 
tone first, allowed to dry, and key plate half¬ 
tone (or stronger color) superimposed on top, 
usin' v “register gauge" or pins. If necessary 
a few approximate “register proofs" may be 
run in the colors wanted, so that the strength 
of tint desired can be judged better and also 
any extra tooling, etc., may be done on the 
plates before the final proving. 

Three and four color work is handled the 
same in general, but more exactness is re 
quired. The inks (especially 3-color), 
strength of run, etc., must be uniform and 


true. The yellow, being more opaque as well 
as generally found more or less as a body 
color over the whole job, is run first. This is 
the slowest drying of the process colors, but 
should be well dried before the next, the red 
(or magenta) is ran. The blue follows, fin¬ 
ishing the job in three-color work. It is semi¬ 
transparent, and dries fairly quickly. In four- 
color, the black is run last, except when using 
transparent process colors, then the order 
may be black, yellow, red and blue. 

In any case, if the job is worth rendering 
in color process it is certainly worth doing 
well, and no pains should be spared in bull¬ 
ing up fine “over-lay" or “make- ready.” Poor- 
proving can ruin the result of an excellent 
color set, besides being misleading for any 
alterations the etcher decides to make on the 
plates. A good proof of a pleasing job should 
be a source of satisfaction to all concerned; 
from the customer and proprietor down to the 
errand boy who delivers the goods. 





“Finished labors are pleasant. 
— 73 — 



FORMULAS 


Rubber Solution 

Rubber cement (pure engravers’). . 5 ounces. 

Benzole . 7 ounces. 

OR 

Pure Virgin rubber .1 ounce. 

Benzole .about 32 ounces. 

Stripping Collodion 

Alcohol (grain) .16 ounces. 

Ether .16 ounces. 

Negative cotton .300 grains. 

Castor oil (best).1 ounce. 

Stripping Bath 

Water . 24 ounces. 

Acetic Acid (Commercial No. 8)...8 ounces. 

Zinc Sensitizing Solution 
(Ink Process) 

Water . 8 ounces. 

Albumen (white of one egg).1 ounce. 

(Or dried albumen powdered, 60 grs.) 
LePage’s Glue (for process works) % ounce. 

Ammonium Bichromate. 20 grains. 

Ammonia (stronger) .14 dram. 

Reverse-Print Re-Developer 

Water . 20 ounces. 

Hydrochloric (strong) . % ounce. 

Zinc Enamel 

Water . 8 ounces. 

LePage’s Glue (for process work) 3!4 ounces. 

Ammonium Bichromate. 120 grains. 

Iron and Ammonium Citrate .... 20 grains. 
Ammonia . y 2 dram. 

Enamel Hardening Solution 

Water . 16 ounces. 

Chromic Acid . 20 grains. 

OR 


74 























Water . 60 ounces. 

Chrome Alum . Y 2 ounce. 

Tannic Acid . % ounce. 

OR (to be used in etching bath) 

2 V 2 drams Chrome Alum to 40 ounces bath. 
Copper Enamel (Glue) 

For general work 

Water . 8 ounces. 

Albumen (whites of 2 eggs) . 2 ounces. 

LePage’s Glue (for process work) . 3 ounces. 

Ammonium Bichromate . 120 °-~'dns. 

Ammonia (stronger) . V 2 dram. 

Copper Enamel (Gum) 

(soft working, for color work) 

Water . 8 ounces. 

Gum Arabic . 1 ounce. 

Ammonium Bichromate . 60 grains. 

Albumen (whites of two eggs) .... 2 ounces. 

Ammonia . Y 2 dram. 

(Dissolve gum, over night, in 6 oz. water, add 
bichromate in 1 oz. and albumen beaten In 
remaining oz. Add ammonia, beat and filter 


Dye Solution 

Analine (violet) .20 grains 

Denatured alcohol .*4 ounce 

Water . 16 ounces 

Dissolve analine in alcohol, then add water. 
Scum Remover 

Water . 16 ounces. 

Potassium Permanganate .30 grains 

Hydrochloric Acid (Commercial) .. Y 2 ounce. 

OR 

Water . 16 ounces. 

Acetic Acid (No. 8) . 12 ounces. 

Salt . 4 ounces. 

OR 

Water . 16 ounces. 

Chromic Acid (crystals).1 dram 

Hydrochloric Acid (Commercial. Y 2 ounce 

Chalk Remover 

Water ... 16 ounces 

Hydrochloric Acid (Commercial).1 ounce 

Salt . 4 ounces. 

OR 


Water, Acetic Acid and Salt; same as scum 
remover. 





























Etching Bath for Copper 

Perchloride of Iron crystals dissolved in earth¬ 
enware jar, add water to test 40 degrees 
Baume. Strain through cloth before using, 
OR 

Carboy iron, as bought. 

Staging Ink. 

Asphaltum . 3 ounces. 

Printers’ Ink (cheap grade).1 ounce. 

Bees-wax (or tallow) .% ounce. 

Thin with turpentine as used. 

Enamel Remover. 

(For removing enamel from etched plates.) 
Potassium Cyanide (sat. sol.) 

OR 


Potassium Cyanide (sat. sol.) and Lye 
(sat. sol.) equal parts. 

Heat plate and scrub with solution. 


- 76 - 







WEIGHTS AND MEASURES 


Apothecaries’ Weight, (used in formulas) 


20 grains .1 scruple. 

o scruples .1 dram. (60 gr » 

& drams .1 oulnce. (480 gr.) 

12 ounces .1 pound. (5760 gr.) 

Avoirdupois Weight, (used in buying) 

27.34 grains . 1 dram. 

16 drams.1 ounce. (437^ gr.) 

16 ounces .1 pound. (7,000 ~~ ’ 

Fluid Measure 

60 minims . \ t . 1 dram. 

8 drams .1 ounce. 

16 ounces . 1 pint. 

2 pints . 1 quart. 

4 quarts . 1 gallon. 

Metric System. (French) 

1 gramme . =15.43 grains. 

1 cubic centimeter (water) = nearly 17 
minims (16.896) and weighs 1 gramme. 

1 meter. =37.37 inches 

Printers’ Measure 

72 points .. 1 inch. 

12 points.1 pica em 

6 pica ems . 1 inch 

13 pica ems . 1 column 

Paper Measure 

24 sheets . 1 quire. 

20 quires . 1 ream 

10 reams.. 1 bale. 


























A Few Chemicals, Their Synonyms 
and Brief Explanations 


(C. P. = Chemically Pure—U. S. P. = United 
States Pharmaceutical Standard) 

Acid—Most acids change blue litmus paper 
to red. 

Should be kept in glass-stoppered 
bottles, except Hydrofluoric, which re¬ 
quires wax or lead containers. 
Acid=Aeetic (absolute) =100 per cent. 

Acid—Acetic (glacial) =80 per cent-99 per ct. 
Acid—Boracic = Boric. 

Acid—Citric—found in juice of lemons, etc. 
Acid—Nitric (C. P.)=Aqua fortis. 

Acid—Nitric (commercial) =38 per cent-40 
per cent. 

Acid—Sulphuric (C. P.)=Oil of Vitriol. 

Acid—Sulphuric (commercial) =66 per cent, j 
***Sulphuric acid should always be j 
poured into cold water, never the 
water into the acid, as there is thus | 
danger of explosion. 

Acid—Tannic = Tannin. 

Albumen=White of Egg=(also in powdered 
form). (60 grs. powdered = 1 oz. fresh) 
Alcohol—(grain) =rectified spirit. 

Alcohol—(wood) = methylated spirit (poison). 
Alcohol—(denatured) =mixture of grain and 
wood alcohols. 

Alkalies=caustics (sodas, potash, ammonia 
etc.) change red litmus paper to blue! 
Aqua Ammonia=Water of Ammonia = Strong¬ 
er Ammonia. (Composed of nitrogen and 
hydrogen.) 

Aqua Fortis—Nitric Acid. 

Asphaltum=asphalt=bitumen=Jew’s pitch. 
Bicarbonate of Soda = Sodium Bicarbonate = 
Baking Soda. 

Bichloride of Mercury = Corrosive Sublimate 
(Very poisonous.) 

Bichromate of Ammonia = Ammonium Bi¬ 
chromate. (All chromates are more or less 
sensitive to light.) 




Bichromate of Potash = Potassium Bichromate. 

Calcium Hydrates Lime. 

Calcium Carbonate = Limestone. 

Carbonate of Soda = Sodiuim Carbonate = Sal 
Soda. 

Carbonate of Potash = Potassium Carbonated- 
Salts Tartar. (Can be used for refining 
silver waste.) 

Copper Sulphate = Sulphate of Copper=Blue- 
stone=Blue Vitriol. 

Cyanide of Potash = Potassium Cyanide. (A 
most powerful poison.) 

Ether—prepared by distilling alcohol and 
sulphuric be id and rectifying the result over 
slacked lime. 

Ferricyanide of Potash = Red Prussiate of 
Potash. 

Ferrocyanide of Potash = Yellow Prussiate 
of Potash. 

Formalin=40 per cent Formaldehv^e. 

Iron Chloride = Perchloride of Iron. 

Potassium Hydrate=Caustic Potash. 

Potassium Permanganate=Permanganate of 
Potash. 

PyroxyJjine = Guncotton = Nitro-cellulose, 
(cotton treated with nitric and sulphuric 
acids). 

Sodium Chloride=Common Salt. 

Sodium Hydrate = Caustic Soda. 

Sodium Nitrate=Chile Saltpetre. 

Water Tests. 

Lime: Two drops of strong oxaiic acid solu¬ 
tion in a glass of water. If milky, lime is 
present. 

Alkalies—Immerse red litmus paper. No 
change indicates no alkali. 

Carbonic Acid—Add equal parts of lime water. 
A precipitate indicates carbonic acid; now 
add muriatic acid and it will effervesce. 

Iron—Add prussiate of potash. Blue color 
indicates iron. 


79 



MISCELLANEOUS 


Ben Day 

The “Ben Day” Process, invented by a 
man of that name, is a rapid mechanical 
method of laying tints in ink on metal prints, 
drawings, Ijine negatives, etc., so as to produce 
those tint effects in the etched plates (usually 
line zinc work). A “Ben Day film”, of suit¬ 
able pattern in relief, is rolled up with Ben 
Day or etching ink. The film is then inverted 
on the metal print (or other surface to be Ben 
Dayed), held in position by the “Ben Day 
Machine”, and the inked relief design trans¬ 
ferred by pressure of a small roller or 
“stylus”. Parts not to receive the design 
must have first been painted over with gum 
gamboge, opaque, or Chinese white; after the 
tint is laid this is washed off with water, 
carrying the ink with it. The design on the 
bare metal remains. The print is then topped 
and etched as usual. 

Stop-Out Work 

The developed ink print is “stained” by 
passing a few seconds in a weak etching bath, 
allowed to oxidize, rinsed off, and dried. The 
parts not wanted in that particular color in 
which the plate is to be printed are rubbed off 
with ammonia, or just under water, using a 
bit of cotton wound on a small stick; or the 
whole plate may be cleaned off with gasoline 
or ammonia, leaving only the stained print. 
Parts wanted are then painted up solid 
(etching or staging ink), or Ben Dayed, and 
plate topped and etched as usual. On large 
work, negative is sometimes opaqued for 
successive colors to remove parts not wanted. 

Reverse Print 

Print (Ink) and develop as usual, but do 
not top . Pass through etching or graining 
bath as in staining, but little more. Roll up 


-so- 




solid with etching ink. Re-develop in Reverse 
Print Developer (see formula). The solution 
dissolves sensitizer on plate, but ink adheres 
to the bare grained surface. Ammonia can be 
used instead of the acid solution if desired. 
Another method is to paint over with shellac 
and reverse by soaking in turpentine. 

Most work in'this effect is done by print¬ 
ing from a “positive” instead of from a neg¬ 
ative. 

Line Work Cut With Screen 

Strip line negative. Strip over ?t film of 
“screen negative” (shadow-dot, made with 
“flash” exposure; one-way screen, made with 
“slit stop”, etc.). Cut and remove parts of 
screen film not wanted. Print and etch as 
usual. 

Screen Rulings 

60—fast rotary news presses. 

85—'flat-bed news, and large “circular” work. 
100—medium grade pamphlets and booklets. 
120—ordinary book work. 

133—ordinary book and catal~~ work. 

150—fine grade book and catalog (good paper). 
200—finest printing on good paper stock; 
(microscopic reproductions, etc., where de¬ 
tail is essential.) 

Combination (Line and Half-tone) 

Strip line negative. Strip over it half-tone 
negative in position. Cut through both films. 
Remove under (or line) film, replace H. T. 
in space, foining carefully, and blot down. 
Any inserts can be stripped into H. T. ?n same 
manner. Print as usual. Etch half-tone 
(complete), then paint in solid and etch line 
work down. 

Double Print 

Strip line negative and half-tone negative 
on separate pieces of glass, plenty large 
enough to cover metal. Place cut metal in 
position on largest negative, and glue three 
small bits of cardboard onto glass, two along 
one side and one at end of metal, for register 
guides. Place negatives (on glass) one over 
other in register. Now glue three more bits 


— 81 — 




of cardboard on second glass directly over, or 
in register with, the first three pieces. 
Print from one negative, having metal evenly 
against the three guides, then print from the 
other negative (regular time on each) with 
metal in same position. Develop and etch as 
usual. 

Tint Plates 

Etch regular half-tone plate as usual; 
best a shade lighter where tint is wanted. 
Print from same negative - onto zinc (either 
ink or enamel process; if enamel, just dye 
and dry off, but do not burn in). Or, print can 
be transferred to zinc, by pulling heavy proof 
from II. T. plate on good paper, and trans¬ 
ferring from paper onto zinc, in proof press. 
Zinc print is then outlined or tooled around 
parts where tint is wanted, the rest routed 
away and trimmed up as usual. Proved, in 
register, with half-tone proof. 

Embossing 

Transfer proof from half-tone, or other 
“key" plate (as for tint plate), on heavy 
type-metal or brass for the purpose. Tool 
parts to be embossed in “intaglio", or sunken 
design, into the metal. Deeper cutting gives 
higher relief in embossing. Tool with as 
broad smooth-blending effect as permissable, 
avoiding sharp cutting comers that are apt 
to cut the paper. Prove by squeezing into 
several thicknesses soft damp blotter. Printer 
builds us “matrix" or “male die" by spread¬ 
ing compound on platen of press, pulling re¬ 
lief impression from plate, and allowing to 
“set" hard. Then prints as usual (but no ink 
or roller used), paper being squeezed into 
relief design between matrix and plate (or 
male and female dies). If plate, or die, is cut 
in soft type metal, it is only used as a pattern 
from which a heavy “electrotype" is made 
for embossing on the press. Dies can also 
be etched, using a “positive" or the reverse 
print method. 


- 82 - 


Spliced Negatives 

Sometimes we are required to make a 
cut (line or half-tone) larger than the ca¬ 
pacity of our camera. Make a negative of 
each half of the copy, including a little more 
than half on each negative to allow for lap 
in matching up. Strip the two halves to¬ 
gether in register, allowing the surplus ends 
to overlap and coincide. Cut through both 
films at one time, after blotting down, cut¬ 
ting as few lines of the design as possible. 
Remove cut ends and work films smoothly 
together with small piece of blotter. 

Clarified Glue 

Any good glue could be used for organic 
matter in sensitizing solutions and enamels 
were it not for being contaminated with 
greases. These greases can be removed (for 
emergency use! by clarifying as follows: soak 
V 2 lb. good ordinary broken glue until soft 
through (about 21 oz. water). Add whites of 
two eggs and three oz. ammonia. Let come 
to slow boil over fire until eggs coagulate, 
skimming off scum that rises. Strain through 
cheese cloth and allow to cool. 

In successful experiments, as above, 
granular sizing glue was used, although good 
cabinet glue is best. The “Duotone” prints 
in Appendix were made with this clarified 
glue enamel. 

Roller Compound 

For composition proving and printing 
rollers: 1 lb. glue (common), 1 qt. best sugar- 
house syrup, 1 pt. glycerine. Soak glue in 
distilled water until soft. Melt over slow fire; 
add syrup; boil for half-hour, skimming off 
scum. Add glycerine and boil few minutes 
longer. Pour into mould around centered 
roller stock, let stand day or two, aH draw 
from mould ready for use. 


Rough dirty spots jn copper half-tone 
plates can sometimes be smoothed up by 








scrubbing with V 2 nitric acid and V 2 water, 
using stout re-etching brush or rubbing over 
with flat piece of wood. 

Zinc plates can be kept smooth and bright 
in etching by adding V 2 oz. of either Glue 
Gum Arabic, or Galic acid to every 40 oz. et¬ 
ching bath. 




INDEX 


Page 
... 2 

... 3 


Preface . 

Introduction . 

Stripping . 

Coating the Negative . 

Stripping Bath . 

Transferring and Reversing 
Difficulties .. 

Metal Printing . 

Sensitizer . 

Polishing . 

Coating the Metal . 

Printing . 

Developing . 

Topping . 

Zinc Etching . 

The Acid Bath. 

4-Way Powdering . 

Successive Bites . 

Clearing the Plate . 

Cleaning^ Bite . 

Zinc Gra'ining . 

Re-Topping . 

Copper Etching . 

Clearing . 

Flat Etch . 

Staging . 

Short Etch . 

Re-Etching . 

Vignettes . 

Cleaning Plate . 

Machine Etching . 

Color Etching . 

Three-color Theory . 

Etching . 


G 

G 

7 

9 

10 

12 

12 

13 

14 

15 

17 

18 

24 

24 

25 

27 

29 

29 

30 

31 

32 

32 

33 

35 

41 

45 

4G 

46 

48 

51 

51 

54 







































Finishing . 58 

Outlining . 58 

The Router . 61 

Trimming Up . 62 

Spotting . 63 

Various Tools and Uses . 64 

“Square Finish” Half-tones . 65 

Re-Engraving . 66 

Zinc Work . 66 

Proving . 68 

Inks . 69 

General Suggestions . 70 

Formulas . 74 

Weights and Measures . 77 

Chemicals . 78 

Miscellaneous . 80 

Ben Day . 80 

Stop-Out Work . 80 

Reverse Print . 80 

Line Work . 81 

Screen Rulings .. 81 

Combination . 81 

Double Print . 81 

Tint Plates . 82 

Embossing . 82 

Spliced Negatives. ... 8a 

Clarified • Glue . 83 

Roller Compound .:. 83 































Commercial Photo-Engraving 



Example of Zlno Etching; 
(with Ben Day Shading) 














































































Direct Zinc Print 



Reverse Print Effect 


REVERSE PRINT 















RUSH 


Lin© Etching Cut With Screen 
(Stripped-Over Screen Nog.) 



Half-Tone (60 screen) on Zinc 
(Newspaper Half-Tone) 









SCREEN RULINGS 
in commercial use. 






















SCREEN RULINGS 
in commercial use 










COMBINATION Line 4 H.T. 
(with Insert) 



DOUBLE PRINT 

















Half-tone with Tint Plates:- 

showing Cut-away Background 

and Soft Vignette. 

Gold Plate;-eolld zinc. 
Pink Plate ;-eolld zlnc ;cut 
Black " ;-H.T.on Copper. 



Showing "Hard Vignette" 
or "Hard Shadow". 








« 


r 


DUOTONE- 

- ( 2-color H .T . ,"fake' ) 
( from E.& V?. photo.) 















Black Proofs of 3-color Process Plates. 







































































































The Evolution of a 

3-color Process Print. -- 

(a) Yellow impression. 

(b) Red impression. 

(c) Red impress, over Yellow 

(d) Blue impression. 

(e) Blue over Yellow and Red 

(=Finished Result) 



























Example of 4-oolor Procese Work . 
(showing 4-oolor Inks used) 





















R.\YM£H 





Embossing Plate 
(hand-cut) 














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